Avian Influenza Weekly Update Number 826 7 January 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 31 December and 6 January 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 31 December 2021, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 6 January 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 6 January 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 456 were fatal (CFR of 53%). The last case was reported from India in July 2021 (source). Human infection with avian influenza A(H5N6) virus Between 31 December and 6 January 2022, no new cases of human infection with avian influenza A(H5N6) virus were notified to WHO in the Western Pacific Region. To date, a total of 58 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 27 deaths have been reported to WHO in the Western Pacific Region since 2014. The last case was reported from China with onset date of 3 December 2021. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Avian Influenza Weekly Update Number 826 | 2 Human infection with avian influenza A(H7N4) virus in China Between 31 December and 6 January 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 31 December and 6 January 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was on 14 February 2017. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus (source). WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighbouring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behaviour to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 31 December and 6 January 2022, no new cases of human infection with avian influenza A(H9N2) were reported from China to WHO in the Western Pacific Region. To date, 20 cases of avian influenza A(H9N2) have been reported to WHO from China in 2021, and a total of 61 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. The last case was reported from China with onset date of 6 December 2021. Human infection with avian influenza A(H10N3) virus Between 31 December and 6 January 2021, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) Avian Influenza Weekly Update Number 826 | 3 virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low (source 1, 2). Animal infection with avian influenza virus Between 31 December and 6 January 2022, 22 new outbreaks of avian influenza were reported to OIE from the Western Pacific Region. (source) On 3 January 2022, Viet Nam reported to OIE 18 outbreaks of highly pathogenic avian influenza A(H5N8) among poultry. Outbreaks occurred in 10 locations; Quảng Trị Province, Quảng Nam Province, Nam Định, Province, Ninh Bình Province, Quảng Ninh Province, Nghệ An Province, Quảng Ngãi Province, Bình Phước Province, Lạng Sơn Province, and Tây Ninh Province. In total there were 20,963 cases including 11,685 deaths among 37,767 susceptible birds, the remaining 26,082 were culled. (source). On 3 January 2022, Republic of Korea reported three outbreaks of highly pathogenic avian influenza A(H5N1) among poultry to OIE. Outbreaks occurred in three locations; Yugok-ri Jeollanam-do, Sinhak-ri Jeollanam-do, Jinseo-ri Jeollabuk-do. In total there were 9 cases including 9 deaths among 83,663 susceptible birds, the remaining 83,654 were culled. (source). On 6 January 2022, Japan reported to OIE one outbreak of highly pathogenic avian influenza (HPAI) A(H5N1) among poultry in Saijo, Ehime Prefecture. In total, there were 30 confirmed cases including 30 deaths among 130,000 susceptible birds, the remaining 129,970 were culled. This is the 7th outbreak HPAI A(H5N1) among poultry reported in the 2021-2022 winter. (source). For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2021 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2021-2022 northern hemisphere influenza season (who.int) 26 February 2021 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2021-22 Northern Hemisphere Influenza Season. 26 February 2021 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 827 14 January 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 7 and 13 January 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 13 January 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 13 January 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 13 January 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 456 were fatal (CFR of 53%). The last case was reported from India in July 2021 (source). Human infection with avian influenza A(H5N6) virus Between 7 and 13 January 2022, five new cases of human infection with avian influenza A(H5N6) virus were notified to WHO in the Western Pacific Region. The first case was a 75-year-old male farmer from Sichuan Province with the onset of illness on 1 December 2021. The case was hospitalized on 4 December 2021 and died on 12 December 2021 due to multiple organ failure. The second case is a 54-year-old male farmer from Sichuan Province with the onset of illness on 8 December 2021. The case was hospitalized on 16 December 2021 and died on 24 December 2021 due to multiple organ failure. The third case is a 51-year-old female from Zhejiang Province with the onset of illness on 15 December 2021. The case was hospitalized on 18 December 2021 with severe pneumonia and remains in critical condition at the time of reporting to WHO. The fourth case is a 53-year-old male farmer from Liuzhou City, Guangxi Province with the onset of illness on 19 December 2021. The case was hospitalized on 23 December 2021 with severe pneumonia and is in a severe condition at the time of reporting to WHO. The fifth case is a 28-year-old male from Liuzhou, Guangxi Province with the onset of illness on 23 December 2021. The case was hospitalized on 23 December 2021 with severe pneumonia and remains in critical condition at the time of reporting. Avian Influenza Weekly Update Number 827 | 2 All the cases had history of exposure to poultry prior to onset of illness and no additional individuals among their respective family members have developed symptoms at the time of reporting. Following investigations, no epidemiological links have been determined among the five cases. To date, a total of 63 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 29 deaths have been reported to WHO in the Western Pacific Region since 2014. The last case was reported from China with onset date of 23 December 2021. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Human infection with avian influenza A(H7N4) virus in China Between 7 and 13 January 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 7 and 13 January 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was on 14 February 2017. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus (source). WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Avian Influenza Weekly Update Number 827 | 3 Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighbouring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behaviour to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 7 and 13 January 2022, four new cases of human infection with avian influenza A(H9N2) were reported from China to WHO in the Western Pacific Region. The first case is a 7-year-old female student from Zhenjiang City, Jiangsu Province with the onset of illness on 27 November 2021. The second case is a 3-year-old female from Huanggang City, Hubei Province with the onset of illness on 7 December 2021. The third case is a 14-year-old female student from Nanning City, Guangxi Province with the onset of illness on 9 December 2021. The case was hospitalized wild a mild condition on 9 December 2021. The fourth case is a 3-year-old male from Huanggang City, Hubei Province with the onset of illness on 13 December 2021. All of the four cases are in mild condition and had already recovered from the disease at the time of reporting to WHO. Before illness onset, the case had a history of poultry exposure. No family members have developed symptoms at the time of reporting. Following investigations, no epidemiological links have been determined among the four cases. To date, 24 cases of avian influenza A(H9N2) have been reported to WHO from China in 2021, and a total of 65 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. The last case was reported from China with onset date of 13 December 2021. Human infection with avian influenza A(H10N3) virus Between 7 and 13 January 2021, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low (source 1, 2). Animal infection with avian influenza virus Between 7 and 13 January 2022, 12 new outbreaks of avian influenza were reported to OIE from the Western Pacific Region. (source) On 7 January 2022, Viet Nam reported to OIE five outbreaks of highly pathogenic avian influenza A(H5N1) among poultry. Outbreaks occurred in five locations; Bình Phước province, Tây Ninh province, Quảng Avian Influenza Weekly Update Number 827 | 4 Trị province, Ninh Bình province and Nghệ An province. In total there were 10,835 cases leading to 6,810 deaths among 18,144 susceptible birds, the remaining 11,334 were culled. (source) On 10 January 2022, the Republic of Korea has reported to OIE two outbreaks of highly pathogenic avian influenza A(H5N1) among poultry in Jeongeup, Jeollabuk-do province and Muan, Jeollanam-do province. In total, there were 300 cases identified among 30,455 susceptible poultry birds. All of the 30,455 birds were culled and disposed. (source) On 13 January 2022, Taiwan, China reported to OIE four outbreaks of avian influenza A(H5N2) among poultry. Outbreaks occurred in four locations; Bade District, Dacheng Township, Douliu City, and Fangyuan Township. In total, there were 7,870 cases leading to 7,870 deaths among 114,592 susceptible birds, the remaining 106,422 birds were culled. (source) On 13 January 2022, Taiwan, China reported to OIE one outbreak of avian influenza A(H5N2) among poultry occurred in Sihu Township, Yunlin County. In total, there were 597 cases leading to 597 deaths among 2,855 susceptible birds, the remaining 2,258 birds were culled. (source) For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2021 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2021-2022 northern hemisphere influenza season (who.int) 26 February 2021 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2021-22 Northern Hemisphere Influenza Season. 26 February 2021 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 828 21 January 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 14 and 20 January 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 20 January 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 20 January 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 20 January 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The last case was reported from India in July 2021 (source). Human infection with avian influenza A(H5N6) virus Between 14 and 20 January 2022, one new case of human infection with avian influenza A(H5N6) virus was notified to WHO in the Western Pacific Region. The case is a 43-year-old female from Huizhou City, Guangdong Province with an onset of illness on 31 December 2021. The case was hospitalized with severe pneumonia on 4 January 2022, and was in a critical condition at the time of reporting. Prior to illness onset, the case had exposure to a live poultry and animal market. No family contacts have developed symptoms at the time of reporting. There have been 34 human cases of avian influenza A(H5N6) reported from China to WHO with onset of illness in 2021. To date, a total of 64 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 29 deaths have been reported to WHO in the Western Pacific Region since 2014. The last case was reported from China with onset date of 23 December 2021. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. Avian Influenza Weekly Update Number 828 | 2 For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Human infection with avian influenza A(H7N4) virus in China Between 14 and 20 January 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 14 and 20 January 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was on 14 February 2017. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus (source). WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighbouring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behaviour to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 14 and 20 January 2022, one new case of human infection with avian influenza A(H9N2) was reported from China to WHO in the Western Pacific Region. The case is a 5-year-old male from Anqing City, Anhui Province with an onset of illness on 13 November 2021. The case had mild illness and has since recovered from the disease at the time of reporting. Before illness onset, the case had a history of exposure to a live poultry market. No family contacts have developed symptoms at the time of reporting. Avian Influenza Weekly Update Number 828 | 3 To date, 21 cases of avian influenza A(H9N2) have been reported to WHO from China with onset of illness in 2021, and a total of 66 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. The last case was reported from China with onset date of 13 December 2021. Human infection with avian influenza A(H10N3) virus Between 14 and 20 January 2021, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low (source 1, 2). Animal infection with avian influenza virus Between 14 and 20 January 2022, three new outbreaks of avian influenza were reported to OIE from the Western Pacific Region. (source) On 14 January 2022, Japan reported to OIE two outbreaks of highly pathogenic avian influenza A(H5N1) among poultry in Saijyo City, Ehime Prefecture. In total, there were 62 cases leading to 62 deaths among 231,000 susceptible birds, the remaining 230,938 birds were culled. (source) On 19 January 2022, Japan reported to OIE one outbreak of highly pathogenic avian influenza A(H5N1) among poultry in Nagoshima, Kagoshima prefecture. In total, there were 150 cases leading to 150 deaths among 111,000 susceptible birds, the remaining 110,850 birds were culled. (source) For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2021 southern hemisphere influenza season (who.int) 24 September 2021 Avian Influenza Weekly Update Number 828 | 4 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2021-2022 northern hemisphere influenza season (who.int) 26 February 2021 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2021-22 Northern Hemisphere Influenza Season. 26 February 2021 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 829 28 January 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 21 and 27 January 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 27 January 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 27 January 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 27 January 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The last case was reported from India in July 2021 (source). Human infection with avian influenza A(H5N6) virus Between 21 and 27 January 2022, two new cases of human infection with avian influenza A(H5N6) virus were notified to WHO in the Western Pacific Region. The first case is a 68-year-old male from Sichuan Province with an onset of illness on 3 January 2022. The case was hospitalized on 4 January and was in a critical condition at the time of reporting. The case had exposure to slaughtered poultry prior to illness onset. No family members have developed symptoms at the time of reporting. The second case is a 55-year-old female from Zhejiang Province with an onset of illness on 6 January 2022. The case was hospitalized on 9 January and was in a critical condition at the time of reporting. Prior to illness onset, the case had exposure to domestic poultry. No family members have developed symptoms at the time of reporting. These are the first two human cases of avian influenza A(H5N6) with the onset of illness reported from China to WHO in 2022. To date, a total of 66 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 29 deaths have been reported to WHO in the Western Pacific Region since 2014. The last case was reported from China with onset date of 31 December 2021. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. Avian Influenza Weekly Update Number 828 | 2 The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Human infection with avian influenza A(H7N4) virus in China Between 21 and 27 January 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 21 and 27 January 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was on 14 February 2017. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus (source). WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighbouring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behaviour to humans as this may have serious public health impacts. Avian Influenza Weekly Update Number 828 | 3 Human infection with avian influenza A(H9N2) virus Between 21 and 27 January 2022, no new cases of human infection with avian influenza A(H9N2) were reported from China to WHO in the Western Pacific Region. To date, 21 cases of avian influenza A(H9N2) have been reported to WHO from China with onset of illness in 2021, and a total of 66 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. The last case was reported from China with onset date of 13 December 2021. Human infection with avian influenza A(H10N3) virus Between 21 and 27 January 2021, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low (source 1, 2). Animal infection with avian influenza virus Between 21 and 27 January 2022, two new outbreaks of avian influenza were reported to OIE from the Western Pacific Region. (source) On 24 January 2022, Japan reported to OIE one outbreak of highly pathogenic avian influenza A(H5N1) among poultry which occurred in Yachimata City, Chiba Prefecture. In total, there were 250 cases leading to 250 deaths among 66,000 susceptible birds, the remaining 65,750 birds were culled. (source) On 26 January 2022, Hong Kong SAR, China reported to OIE one outbreak of highly pathogenic avian influenza A(H5N1). Avian influenza A(H5N1) virus was detected in one dead wild bird found in the Mai Po Nature Reserve in Yuen Long. (source) For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Avian Influenza Weekly Update Number 828 | 4 Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2021 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2021-2022 northern hemisphere influenza season (who.int) 26 February 2021 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2021-22 Northern Hemisphere Influenza Season. 26 February 2021 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 830 4 February 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 28 January and 3 February 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 3 February 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 3 February 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 3 February 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The last case was reported from India in July 2021 (source). Human infection with avian influenza A(H5N6) virus Between 28 January and 3 February 2022, no new cases of human infection with avian influenza A(H5N6) virus were notified to WHO in the Western Pacific Region. To date, a total of 66 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 29 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Avian Influenza Weekly Update Number 830 | 2 Human infection with avian influenza A(H7N4) virus in China Between 28January and 3 February 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 28 January and 3 February 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was on 14 February 2017. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus (source). WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighbouring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behaviour to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 28 January and 3 February 2022, no new case of human infection with avian influenza A(H9N2) were reported from China to WHO in the Western Pacific Region. To date, 21 cases of avian influenza A(H9N2) have been reported to WHO from China with onset of illness in 2021, and a total of 66 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. The last case was reported from China with onset date of 13 December 2021. Human infection with avian influenza A(H10N3) virus Between 28January and 3 February 2022, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected Avian Influenza Weekly Update Number 830 | 3 in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low (source 1, 2). Animal infection with avian influenza virus Between 28 January and 3 February 2022, two new outbreaks of avian influenza were reported to OIE from the Western Pacific Region. (source) On 28 January 2022, Republic of Korea reported to OIE six outbreaks of highly pathogenic avian influenza A(H5N1) among poultry which occurred in Cheonan, Chungcheongnam-do province; Hwaseong, Gyeonggi-do province; Jincheon, Chungcheonbuk-do province. In total, there were 200 cases among 618,743 susceptible birds, the remaining 618,743 birds were culled. (source) On 28 January 2022, Japan, reported to OIE one outbreak of highly pathogenic avian influenza A(H5N1) among poultry which occurred in a duck farm, in Chiba prefecture. In total, there was 1 case leading to 1 death and to among 5,800 susceptible poultry with 5,799 susceptible poultry culled.. (source) For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2021 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2021-2022 northern hemisphere influenza season (who.int) 26 February 2021 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2021-22 Northern Hemisphere Influenza Season. 26 February 2021 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 831 11 February 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 4 February and 10 February 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 10 February 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 10 February 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 10 February 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The last case was reported from India in July 2021 (source). Human infection with avian influenza A(H5N6) virus Between 4 February and 10 February 2022, no new cases of human infection with avian influenza A(H5N6) virus were notified to WHO in the Western Pacific Region. To date, a total of 66 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 29 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Avian Influenza Weekly Update Number 830| 2 Human infection with avian influenza A(H7N4) virus in China Between 4 February and 10 February 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 4 February and 10 February 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was on 14 February 2017. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus (source). WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighbouring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behaviour to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 4 February and 10 February 2022, no new cases of human infection with avian influenza A(H9N2) were reported from China to WHO in the Western Pacific Region. To date, 21 cases of avian influenza A(H9N2) have been reported to WHO from China with onset of illness in 2021, and a total of 66 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. The last case was reported from China with onset date of 13 December 2021. Human infection with avian influenza A(H10N3) virus Between 4 February and 10 February 2022, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected Avian Influenza Weekly Update Number 830| 3 in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low (source 1, 2). Animal infection with avian influenza virus Between 4 February and 10 February 2022, four reports of new outbreaks of avian influenza were reported to OIE from the Western Pacific Region (source). On 5 February 2022, the Republic of Korea reported to OIE four outbreaks of highly pathogenic avian influenza A(H5N1) among poultry in Cheonan, Yesan in Chungcheongnam-do Province; Jincheon in Chungcheongbuk-do Province; and Gimje in Jeollabuk-do Province. In total, there were 1,199 cases leading to 199 deaths among 1,314,739 susceptible birds, the remaining 1,314,540 poultry were culled (source). On 7 February 2022, Taiwan, China reported to OIE three outbreaks of highly pathogenic avian influenza A(H5N2) among poultry in Changjua City, Taiwan, China. In total, there were 7,807 cases leading to 7,807 deaths among 89,847 susceptible birds, the remaining 82,040 poultry were culled (source). On 10 February 2022, the Republic of Korea reported to OIE six outbreaks of highly pathogenic avian finluenza A(H5N1) among non-poultry. Avian influenza A(H5N1) viruses were detected in four wild birds leading to four deaths in Gimhae, Gyeongsangnam-do Province; and Cheorwon, Gangwon-do Province. Avian Influenza A(H5N1) was identified in two fecal samples of wild birds in Hwaseong, Gyeonggi-do Province (source). On 10 February 2022, the Republic of Korea reported to OIE ten outbreaks of highly pathogenic avian influenza A(H5N1) among poultry in Asan, Yesan, Boryeong, Cheonan in Chungcheongnam-do Province; Jincheon in Chungcheongbuk-do Province; Pyeongtaek in Gyeonggi-do Province; and Jeongeup, Buan in Jeollabuk-do Province. In total, there were 3,580 cases leading to 3,480 deaths among 832,500 susceptible birds,the remaining 819,920 poultry were culled (source). For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2021 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 Avian Influenza Weekly Update Number 830| 4 • Recommended composition of influenza virus vaccines for use in the 2021-2022 northern hemisphere influenza season (who.int) 26 February 2021 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2021-22 Northern Hemisphere Influenza Season. 26 February 2021 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 832 18 February 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 11 February and 17 February 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 17 February 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 17 February 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 17 February 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The last case was reported from India in July 2021 (source). Human infection with avian influenza A(H5N6) virus Between 11 February and 17 February 2022, 4 new cases of human infection with avian influenza A(H5N6) virus were notified to WHO in the Western Pacific Region. To date, a total of 72 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 30 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Avian Influenza Weekly Update Number 831 | 2 Human infection with avian influenza A(H7N4) virus in China Between 11 February and 17 February 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory- confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 11 February and 17 February 2022, no new case of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was on 14 February 2017. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus (source). WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighbouring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behaviour to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 11 February and 17 February 2022, no new case of human infection with avian influenza A(H9N2) were reported from China to WHO in the Western Pacific Region. To date, 6 cases of avian influenza A(H9N2) have been reported to WHO from China with onset of illness in 2022, and a total of 71 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. The last case was reported from China with onset date of 28 January 2022. Human infection with avian influenza A(H10N3) virus Between 11 February and 17 February 2022, no new case of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected Avian Influenza Weekly Update Number 831 | 3 in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low (source 1, 2). Animal infection with avian influenza virus Between 11 February and 17 February 2022, two reports of new outbreaks of avian influenza were reported to OIE from the Western Pacific Region (source). On 13 February 2022, the Viet Nam reported to OIE Three outbreaks of highly pathogenic avian finluenza A(H5N1) among poultry in Ha Noi, Quang Binh and Quang Nam Province. (source). On 15 February 2022, the Republic of Korea reported to OIE four outbreaks of highly pathogenic avian influenza A(H5N1) among poultry in DangJin in Chungcheongnam-do Province; Jincheon, Goesan in Chungcheongbuk-do Province. In total, there were 755 cases leading to 55 deaths among 226,048 susceptible birds, the remaining 225,293 poultry were culled (source). Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2021 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2021-2022 northern hemisphere influenza season (who.int) 26 February 2021 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2021-22 Northern Hemisphere Influenza Season. 26 February 2021 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 833 25 February 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 18 February and 24 February 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 24 February 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 24 February 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 24 February 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The last case was reported from India in July 2021 (source). Human infection with avian influenza A(H5N6) virus Between 18 February and 24 February 2022, one new case of human infection with avian influenza A(H5N6) virus was notified to WHO in the Western Pacific Region. To date, a total of 72 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 30 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Avian Influenza Weekly Update Number 833 | 2 Human infection with avian influenza A(H7N4) virus in China Between 18 February and 24 February 2022, no new case of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 18 February and 24 February 2022, no new case of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was on 14 February 2017. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus (source). WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighbouring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behaviour to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 18 February and 24 February 2022, no new case of human infection with avian influenza A(H9N2) were reported from China to WHO in the Western Pacific Region. To date, 6 cases of avian influenza A(H9N2) have been reported to WHO from China with onset of illness in 2022, and a total of 71 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. The last case was reported from China with onset date of 28 January 2022. Human infection with avian influenza A(H10N3) virus Between 18 February and 24 February 2022, no new case of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected Avian Influenza Weekly Update Number 833 | 3 in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low (source 1, 2). Animal infection with avian influenza virus Between 18 February and 24 February 2022, two reports of new outbreaks of avian influenza were reported to OIE from the Western Pacific Region (source). On 18 February 2022, Japan reported to OIE two outbreaks of highly pathogenic avian influenza A(H5N1) among poultry in Kuji in Iwate Prefecture. In total, there were 236 cases leading to 236 deaths among 45,000 susceptible birds, and the remaining 44,764 poultry were culled (source). On 18 February 2022, the Philippines reported to OIE four outbreaks of highly pathogenic avian influenza A(H5N1) among poultry in Bulacan and Pampanga provinces. In total there were 98 cases leading to 42,245 deaths among 78,280 susceptible birds and the remaining 36,035 were culled. This is the first notification of the avian influenza A(H5N1) strain among poultry in the Philippines (source). For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2021 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2021-2022 northern hemisphere influenza season (who.int) 26 February 2021 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2021-22 Northern Hemisphere Influenza Season. 26 February 2021 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 834 4 March 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 25 February and 3 March 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 3 March 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 3 March 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 3 March 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The last case was reported from India in July 2021 (source). Human infection with avian influenza A(H5N6) virus Between 25 February and 3 March 2022, three new cases of human infection with avian influenza A(H5N6) virus were notified to WHO in the Western Pacific Region. The first of the three cases is a 6-year-old female from Yangzhou, Jiangsu province, with an onset of illness on 20 January 2022. The case was hospitalized on 25 January for severe pneumonia and was in a critical condition at the time of reporting. Prior to illness onset, the case had exposure to backyard live poultry. The second of the three cases is a 48-year-old male, an automobile mechanic, from Chengdu, Sichuan province, with an onset of illness on 23 January 2022. The case was hospitalized on 24 January for severe pneumonia and was in a critical condition at the time of reporting. Prior to illness onset, the case had exposure to a live poultry market. The last of the three cases is a 35-year-old male farmer from Hechi in Guangxi, with an onset of illness on 31 January 2022. The case was hospitalized on 05 February for severe pneumonia and was in a critical condition at the time of reporting. Prior to illness onset, the case had exposure to backyard sick and/ordead poultry. To date, a total of 72 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 30 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from Avian Influenza Weekly Update Number 834 | 2 the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Human infection with avian influenza A(H7N4) virus in China Between 25 February and 3 March 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 25 February and 3 March 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was on 14 February 2017. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus (source). WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighbouring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behaviour to humans as this may have serious public health impacts. Avian Influenza Weekly Update Number 834 | 3 Human infection with avian influenza A(H9N2) virus Between 25 February and 3 March 2022, one new case of human infection with avian influenza A(H9N2) was reported from China to WHO in the Western Pacific Region. The case is a 51-year-old female private vendor from Jiangxi Province with potential exposure in Jingdezhen City, Jiangxi. The case had an onset of illness on 11 January 2022, was hospitalized on 17 January for pneumonia, and has since recovered. Before illness onset, the case had a history of exposure to a live poultry market. To date, a total of 71 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. Human infection with avian influenza A(H10N3) virus Between 25 February and 3 March 2022, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low (source 1, 2). Animal infection with avian influenza virus Between 25 February and 3 March 2022, one new report of outbreaks of avian influenza was reported to OIE from the Western Pacific Region (source). On 3 March 2022, Taiwan, China reported to OIE four outbreaks of highly pathogenic avian influenza A(H5N2) among poultry in Yunlin County and Pingtung County, Taiwan, China. In total, there were 6,704 cases leading to 6,704 deaths among 50,822 susceptible birds, and the remaining 44,118 poultry were culled (source). For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Avian Influenza Weekly Update Number 834 | 4 Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2022 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2022-2023 northern hemisphere influenza season (who.int) 25 February 2022 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2022-23 Northern Hemisphere Influenza Season 25 February 2022 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 835 11 March 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 4 March 2022 and 10 March 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 10 March 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 10 March 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 10 March 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The last case was reported from India in July 2021 (source). Human infection with avian influenza A(H5N6) virus Between 4 March 2022 and 10 March 2022, two new cases of human infection with avian influenza A(H5N6) virus were notified to WHO in the Western Pacific Region. The first case is 12-year-old female student from Liuzhou, Guangxi province, with onset of illness on 17 November 2021. The case was hospitalized on 20 November 2021 and died on 4 December 2021. Prior to illness onset, the case had exposure to live poultry market. The second case is 79-year-old retired male from Liuzhou, Guangxi province, with onset of illness on 18 November 2021. The case was hospitalized on 22 November 2021 and died on 3 December 2021. Prior to illness onset, the case had exposure to live poultry market. To date, a total of 74 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 32 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. Avian Influenza Weekly Update Number 835 | 2 For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Human infection with avian influenza A(H7N4) virus in China Between 4 March 2022 and 10 March 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 4 March 2022 and 10 March 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was on 14 February 2017. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus (source). WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighbouring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behaviour to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 4 March 2022 and 10 March 2022, no new cases of human infection with avian influenza A(H9N2) were reported from China to WHO in the Western Pacific Region. To date, a total of 71 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. Avian Influenza Weekly Update Number 835 | 3 Human infection with avian influenza A(H10N3) virus Between 4 March 2022 and 10 March 2022, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low (source 1, 2). Animal infection with avian influenza virus Between 4 March 2022 and 10 March 2022, twenty five new outbreaks of avian influenza among birds were reported to OIE from the Western Pacific Region (source). On 4 March 2022, Japan reported to OIE seventeen outbreaks of highly pathogenic avian influenza A(H5N1) among wild birds in Kuji, Iwate province; Rishirifuji, Shari, Rausu, Nemuro, Shibetsu, and Erimo in Hokkaido province; and Kyoto, Kyoto Province. In total, there were 67 cases of wild birds leading to 66 deaths (source). On 4 March 2022, the Philippines reported to OIE eight outbreaks of highly pathogenic avian influenza A(H5N1) among poultry in San Rafael in Bulacan Province; Mexico and Minalin in Pampanga Province; Bula and Sipocot in Camarines Sur Province; and Victoria in Laguna Province. In total, there were 139 cases leading to 2,145 deaths among 4,918 susceptible birds, and the remaining 2,773 poultry were culled (source). For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) ` • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2022 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 Avian Influenza Weekly Update Number 835 | 4 • Recommended composition of influenza virus vaccines for use in the 2022-2023 northern hemisphere influenza season (who.int) 25 February 2022 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2022-23 Northern Hemisphere Influenza Season 25 February 2022 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 836 18 March 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 11 March 2022 and 17 March 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 17 March 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 17 March 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 17 March 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The last case was reported from India in July 2021 (source). Human infection with avian influenza A(H5N6) virus Between 11 March 2022 and 17 March 2022, one new case of human infection with avian influenza A(H5N6) virus were notified to WHO in the Western Pacific Region. The case is a 51-year-old female, a farmer from Nanchang City, Jiangxi Province, with an onset of illness on 20 February 2022. The case was hospitalized for severe pneumonia on 23 February 2022 and was in a critical condition at the time of reporting. Prior to illness onset, the case had exposure to live backyard chickens, and had slaughtered, cleaned and cooked the chickens. No signs of infection or illness were reported from the chickens. However, environmental samples collected from the patient’s residence tested positive for H5. No other family members have developed symptoms at the time of reporting. To date, a total of 75 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 32 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. Avian Influenza Weekly Update Number 836 | 2 For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Human infection with avian influenza A(H7N4) virus in China Between 11 March 2022 and 17 March 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory- confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 11 March 2022 and 17 March 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory- confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was on 14 February 2017. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus (source). WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighbouring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behaviour to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 11 March 2022 and 17 March 2022, two cases of human infection with avian influenza A(H9N2) were reported from China to WHO in the Western Pacific Region. The first case is a 2-year old female, from Chuzhou, Anhui province, with onset of symptoms on 29 January 2022. The patient had mild disease, did not require hospitalization and has since recovered. Prior to illness onset, the case had exposure to live poultry market. The environmental samples were collected from the suspected live poultry market, and tested positive for A(H9). Avian Influenza Weekly Update Number 836 | 3 The second case is a 5-year old female, from Yangquan, Shanxi province, with onset of symptoms on 3 November 2021. The case was laboratory confirmed on 16 November 2021. The patient had mild disease and has since recovered. To date, a total of 72 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. Human infection with avian influenza A(H10N3) virus Between 11 March 2022 and 17 March 2022, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low (source 1, 2). Animal infection with avian influenza virus Between 11 March 2022 and 17 March 2022, no new outbreaks of avian influenza among birds were reported to OIE from the Western Pacific Region (source). For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) ` • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2022 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2022-2023 northern hemisphere influenza season (who.int) 25 February 2022 Avian Influenza Weekly Update Number 836 | 4 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2022-23 Northern Hemisphere Influenza Season 25 February 2022 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 837 25 March 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 18 March 2022 and 24 March 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 24 March 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 24 March 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 24 March 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The last case was reported from India in July 2021 (source). Human infection with avian influenza A(H5N6) virus Between 18 March 2022 and 24 March 2022, no new cases of human infection with avian influenza A(H5N6) virus were notified to WHO in the Western Pacific Region. To date, a total of 75 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 32 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Avian Influenza Weekly Update Number 837 | 2 Human infection with avian influenza A(H7N4) virus in China Between 18 March 2022 and 24 March 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory- confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 18 March 2022 and 24 March 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory- confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was in 2019. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus (source). WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighboring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behavior to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 18 March 2022 and 24 March 2022, one case of human infection with avian influenza A(H9N2) was reported from Cambodia to WHO in the Western Pacific Region. The case is a 13-month-old female from Chi Kreng district, Siem Reap province, Cambodia . The case has no underlying conditions; symptoms of runny nose and cough began on 27 February and as the case did not improve, she was admitted to Angkor Hospital for Children (AHC) on 3 March. She had mild dyspnea, fever (>38 ° C), cough and sore throat on admittance. She improved overnight and was discharged on 4 March. No symptoms in the rest of the family had been observed, but many children in the village were observed with Influenza-Like Illness (ILI) symptoms. Nasal swabs were collected from thirteen family members and close contacts from the village; none tested positive for influenza. Some poultry in the village were sick/died in the last couple of months and each family keep chickens in the backyard, including where the case lived. Sixteen chicken samples were collected from five households including that of the index case. Four samples, all from the case household, were positive for avian influenza A/H9N2. Avian Influenza Weekly Update Number 837 | 3 This is the second human influenza A(H9N2) detection in Cambodia. Previously, one A(H9N2) case, a three- year-old boy also from the Siem Reap Province and with mild illness has been reported to WHO on 17 March 2021. To date, a total of 74 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. Human infection with avian influenza A(H10N3) virus Between 18 March 2022 and 24 March 2022, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low (source 1, 2). Animal infection with avian influenza virus Between 18 March 2022 and 24 March 2022, four new reports of outbreaks of avian influenza among birds were reported to OIE from the Western Pacific Region (source). On 18 March 2022, Japan reported to OIE about highly pathogenic avian influenza A(H5) in 1 case of wild bird leading to 1 death in Nihonmatsu in Fukushima province (source). On 21 March 2022, Japan reported to OIE twenty-eight outbreaks of highly pathogenic avian influenza A(H5N1) among wild birds in Kuji in Iwate prefecture and Shibetsu, Nemuro in Hokkaido. In total, there were 67 cases leading to 67 deaths (source). On 23 March 2022, Philippines reported to OIE 1 outbreak of highly pathogenic avian influenza A(H5N8) among poultry in Santa Ana in Pampanga Province. In total, there were 10 cases leading to no deaths among 2,730 susceptible birds (source). On 23 March 2022, Philippines reported to OIE sixteen outbreaks of highly pathogenic avian influenza A(H5N1) among poultry in Guimba, Cuyapo, Muñoz City, Aliaga, and Santo Domingo in Nueva Ecija Province; Bula, Balatan, Libmanan, Nabua, Goa, and Baao in Camarines Sur Province; San Pedro and Victoria in Laguna Province; Hermosa in Bataan Province; La Paz in Tarlac Province. In total, there were 15,937 cases leading to 15,899 deaths among 2,0831 susceptible birds, and the remaining 4,906 poultry were culled (source). Avian Influenza Weekly Update Number 837 | 4 For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) ` • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2022 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2022-2023 northern hemisphere influenza season (who.int) 25 February 2022 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2022-23 Northern Hemisphere Influenza Season 25 February 2022 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 838 1 April 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 25 March 2022 and 31 March 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 31 March 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 31 March 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 31 March 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The latest case was reported from United Kingdom in January 2022 (source). Human infection with avian influenza A(H5N6) virus Between 25 March 2022 and 31 March 2022, no new cases of human infection with avian influenza A(H5N6) virus were notified to WHO in the Western Pacific Region. To date, a total of 75 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 32 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Avian Influenza Weekly Update Number 838| 2 Human infection with avian influenza A(H7N4) virus in China Between 25 March 2022 and 31 March 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory- confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 25 March 2022 and 31 March 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory- confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was in 2019. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus (source). WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighboring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behavior to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 25 March 2022 and 31 March 2022, no new cases of human infection with avian influenza A(H9N2) were reported to WHO in the Western Pacific Region. To date, a total of 74 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. Human infection with avian influenza A(H10N3) virus Between 25 March 2022 and 31 March 2022, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected Avian Influenza Weekly Update Number 838| 3 in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low (source 1, 2). Animal infection with avian influenza virus Between 25 March 2022 and 31 March 2022, four new reports of outbreaks of avian influenza among birds were reported to OIE from the Western Pacific Region (source). On 25 March 2022, the Philippines reported four outbreaks of highly pathogenic avian influenza A(H5N1) among poultry in Sultan Kudarat Province. This is a first occurrence in this area. In total there were 114 cases leading to 69 deaths among 3,205 susceptible birds and the remaining 3,136 were culled (source). On 27 March 2022, the Republic of Korea reported nineteen outbreaks of highly pathogenic avian influenza A(H5N1) among non-poultry in Gangwon Province, Gyeonggi Province, and Seoul. In total there were 46 cases leading to 45 deaths (source). On 28 March 2022, the Taiwan, China reported five outbreaks of highly pathogenic avian influenza A(H5N2) among poultry in Tainan, New Taipei, Yunlin, Changhua in Taiwan. In total there were 8,507 cases leading to 8,507 deaths among 41,994 susceptible birds and the remaining 33,487 were culled (source). On 30 March 2022, Japan reported one outbreak of highly pathogenic avian influenza A(H5N1) among poultry in Miyagi province. In total there were 250 cases leading to 250 deaths among 32,000 susceptible birds and the remaining 31,750 were culled (source). For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) ` • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2022 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2022-2023 northern hemisphere influenza season (who.int) 25 February 2022 Avian Influenza Weekly Update Number 838| 4 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2022-23 Northern Hemisphere Influenza Season 25 February 2022 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 839 8 April 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 1 April 2022 and 7 April 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 7 April 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 7 April 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 7 April 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The latest case was reported from United Kingdom in January 2022. Human infection with avian influenza A(H5N6) virus Between 1 April 2022 and 7 April 2022, one new case of human infection with avian influenza A(H5N6) virus was notified to WHO in the Western Pacific Region. The case is a 28-year-old male slaughterhouse worker from Puyang city, Henan province, with an onset of illness on 18 March 2022. The case was hospitalized on 19 March 2022. Prior to illness onset, the case was exposed to live poultry while slaughtering ducks coming from small local poultry farms. To date, a total of 75 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 32 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. Avian Influenza Weekly Update Number 839| 2 For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Human infection with avian influenza A(H7N4) virus in China Between 1 April 2022 and 7 April 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 1 April 2022 and 7 April 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was in 2019. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus (source). WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighboring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behavior to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 1 April 2022 and 7 April 2022, no new cases of human infection with avian influenza A(H9N2) were reported to WHO in the Western Pacific Region. To date, a total of 74 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. Human infection with avian influenza A(H10N3) virus Avian Influenza Weekly Update Number 839| 3 Between 1 April 2022 and 7 April 2022, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low. Animal infection with avian influenza virus Between 1 April 2022 and 7 April 2022, five new reports of outbreaks of avian influenza among birds were reported to OIE from the Western Pacific Region. On 5 April 2022, the Republic of Korea reported two outbreaks of highly pathogenic avian influenza A(H5N1) among non-poultry in Goseong in Gangwon Province. In total there were 4 cases leading to 4 deaths (source). On 6 April 2022, the Philippines reported eight outbreaks of highly pathogenic avian influenza A(H5N1) among poultry in Sultan Kudarat Province and North Cotabato Province. In total there were 658 cases leading to 606 deaths among 6,313 susceptible birds and the remaining 5,707 were culled. On 7 April 2022, the Philippines reported fourteen outbreaks of highly pathogenic avian influenza A(H5N1) among poultry in Bataan Province, Benguet Province, Laguna Province, Nueva Ecija Province, Pampanga Province, Tarlac Province. In total there were 12,214 cases and 12,241 deaths among 42,752 susceptible birds and the remaining 30,328 were culled. On 7 April 2022, Japan reported nine outbreaks of highly pathogenic avian influenza A(H5N1) among non- poultry in Rebun, Nemuro , Rausu, and Hamatonbetsu in Hokkaido Province; in Kuji in Iwate Province. In total, there were 78 cases leading to 78 deaths. On 7 April 2022, Japan reported three outbreaks of highly pathogenic avian influenza A(H5) among non- poultry in Kuji in Iwate Province; in Saroma, Kitami in Hokkaido Province. In total, there were 3 cases leading to 2 deaths. For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 Avian Influenza Weekly Update Number 839| 4 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2022 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2022-2023 northern hemisphere influenza season (who.int) 25 February 2022 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2022-23 Northern Hemisphere Influenza Season 25 February 2022 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 840 15 April 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 8 April 2022 and 14 April 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 14 April 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 14 April 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 14 April 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The latest case was reported from United Kingdom in January 2022. Human infection with avian influenza A(H5N6) virus Between 8 April 2022 and 14 April 2022, one new case of human infection with avian influenza A(H5N6) virus was notified to WHO in the Western Pacific Region. The case is a 53-year-old female retiree from Zhenjiang city, Jiangsu province, with an onset of illness on 24 March 2022. The case was hospitalized on 26 March 2022. Prior to illness onset, the case had exposure to live poultry market which sold a range of poultry, including duck, chicken and pigeon. To date, a total of 76 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 32 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: Avian Influenza Weekly Update Number 840| 2 https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Human infection with avian influenza A(H7N4) virus in China Between 8 April 2022 and 14 April 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 8 April 2022 and 14 April 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was in 2019. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus. WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighboring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behavior to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 8 April 2022 and 14 April 2022, no new cases of human infection with avian influenza A(H9N2) were reported to WHO in the Western Pacific Region. To date, a total of 74 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. Human infection with avian influenza A(H10N3) virus Avian Influenza Weekly Update Number 840| 3 Between 8 April 2022 and 14 April, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low . Animal infection with avian influenza virus Between 8 April 2022 and 14 April 2022, three new reports of outbreaks of avian influenza among birds were reported to OIE from the Western Pacific Region. On 11 April 2022, Japan reported to OIE about highly pathogenic avian influenza A(H5N1) in 1 case of raccoon dog leading to 1 death in Hokkaido in Sapporo Province. On 10 April 2022, the Republic of Korea reported to OIE one outbreak of highly pathogenic avian influenza A(H5N1) among poultry in Gimhae in Gyeongsang-namdo Province. In total, there were 650 cases leading to 650 deaths. On 12 April 2022, Japan reported to OIE one outbreak of highly pathogenic avian influenza A(H5N1) among poultry in Aomori in Yokohama Province. In total, there were 90 cases leading to 90 deaths. For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2022 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2022-2023 northern hemisphere influenza season (who.int) 25 February 2022 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 Avian Influenza Weekly Update Number 840| 4 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2022-23 Northern Hemisphere Influenza Season 25 February 2022 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 841 22 April 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 15 April 2022 and 21 April 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 21 April 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 21 April 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 21 April 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The latest case was reported from United Kingdom in January 2022. Human infection with avian influenza A(H5N6) virus Between 15 April 2022 and 21 April 2022, one new case of human infection with avian influenza A(H5N6) virus was notified to WHO in the Western Pacific Region. The case is a 56-year-old male from Deyang city, Sichuan province, with an onset of illness on 31 March 2022. The case was hospitalized on 4 April 2022 and was in a severe condition at the time of reporting. Prior to illness onset, the case had exposure to dead backyard chickens, however, none of the environmental samples collected tested positive for H5. To date, a total of 78 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 32 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. Avian Influenza Weekly Update Number 841 | 2 For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Human infection with avian influenza A(H7N4) virus in China Between 15 April 2022 and 21 April 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 15 April 2022 and 21 April 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was in 2019. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus. WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighboring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behavior to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 15 April 2022 and 21 April 2022, no new cases of human infection with avian influenza A(H9N2) were reported to WHO in the Western Pacific Region. To date, a total of 74 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. Avian Influenza Weekly Update Number 841 | 3 Human infection with avian influenza A(H10N3) virus Between 15 April 2022 and 21 April, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low. Animal infection with avian influenza virus Between 15 April 2022 and 21 April 2022, two new reports of outbreaks of avian influenza among animals were reported to OIE from the Western Pacific Region. On 18 April 2022, Japan reported to OIE about highly pathogenic avian influenza A(H5N1) in one case of raccoon dog leading to one death in Hokkaido in Sapporo Province. This is the second confirmed case of highly pathogenic avian influenza A(H5N1) in raccoon dog in Sapporo in Hokkaido Province since the previous report on 12 April 2022. On 19 April 2022, Chinese Taipei reported to OIE one outbreak of highly pathogenic avian influenza A(H5N2) among poultry in Chiayi County. In total, there were 2,050 cases leading to 2,050 deaths. For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2022 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2022-2023 northern hemisphere influenza season (who.int) 25 February 2022 Avian Influenza Weekly Update Number 841 | 4 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2022-23 Northern Hemisphere Influenza Season 25 February 2022 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 842 29 April 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 22 April 2022 and 28 April 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 21 April 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 21 April 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 21 April 2022, there have been 863 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 863 cases, 455 were fatal (CFR of 53%). The latest case was reported from United Kingdom in January 2022. Human infection with avian influenza A(H5N6) virus Between 22 April 2022 and 28 April 2022, no new case of human infection with avian influenza A(H5N6) virus was notified to WHO in the Western Pacific Region. To date, a total of 78 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 32 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Avian Influenza Weekly Update Number 842 | 2 Human infection with avian influenza A(H7N4) virus in China Between 22 April 2022 and 28 April 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 22 April 2022 and 28 April 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was in 2019. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus. WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighboring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behavior to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 22 April 2022 and 28 April 2022, no new cases of human infection with avian influenza A(H9N2) were reported to WHO in the Western Pacific Region. To date, a total of 74 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. Human infection with avian influenza A(H10N3) virus Between 22 April 2022 and 28 April, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected Avian Influenza Weekly Update Number 842 | 3 in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low. Animal infection with avian influenza virus Between 22 April 2022 and 28 April 2022, three new reports of outbreaks of avian influenza among birds were reported to OIE from the Western Pacific Region. On 25 April 2022, Japan reported to OIE four outbreaks of highly pathogenic avian influenza A(H5N1) among poultry in Aomori in Yokohama Province, Shiraoi and Abashiri in Hokkaido Province, and Akita in Daisen Province. In total there were 150 cases leading to 150 deaths among 631,000 susceptible birds, and the remaining 63,0850 poultry were culled. On 25 April 2022, Japan reported to OIE about highly pathogenic avian influenza A(H5) in 2 cases of white- tailed eagle in Bihoro and Saroma in Hokkaido Province. On 27 April 2022, Japan reported to OIE about new cases of highly pathogenic avian influenza A(H5N1) among non-poultry in Sapparo, Mukawa, Okoppe, Kitami, Kushiro City, Rausu, Shari and Ozora of Hokkaido Province, and Hachimantai and Kuji of Iwate Province. In total there were 128 cases leading to 128 deaths. For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2022 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2022-2023 northern hemisphere influenza season (who.int) 25 February 2022 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2022-23 Northern Hemisphere Influenza Season 25 February 2022 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 843 6 May 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 29 April 2022 and 5 May 2022, no new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region. As of 28 April 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 21 April 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 5 May 2022, there have been 864 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 864 cases, 456 were fatal (CFR of 53%). The latest case was reported from United States of America in April 2022. Human infection with avian influenza A(H5N6) virus Between 29 April 2022 and 5 May 2022, no new case of human infection with avian influenza A(H5N6) virus was notified to WHO in the Western Pacific Region. To date, a total of 78 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 32 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Avian Influenza Weekly Update Number 843 | 2 Human infection with avian influenza A(H3N8) virus On 25 April 2022, one new case of human infection with avian influenza A(H3N8) virus was notified to WHO in the Western Pacific Region. This is the first human case of H3N8 reported globally. The case is a 4-year-old child, male from Zhumadian city in Henan Province, China, with an onset of illness on 5 April 2022. The case was hospitalized on 10 April 2022 and was in critical condition at the time of reporting. The case had exposure to chickens which included black-bone chickens that had been raised in his backyard. The patient participated in the cooking and consumption of four chickens and two black- bone chickens before onset of illness. Clinical observation and sampling of the case’s close contacts revealed no infection or symptoms of illness. To date, only one laboratory-confirmed cases of human infection with influenza A(H3N8) virus with no death has been reported to WHO in the Western Pacific Region. Human infection with avian influenza A(H7N4) virus in China Between 29 April 2022 and 5 May 2022, no new cases of human infection with avian influenza A(H7N4) virus were reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 29 April 2022 and 5 May 2022, no new cases of human infection with avian influenza A(H7N9) virus were reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was in 2019. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus. WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighboring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behavior to humans as this may have serious public health impacts. Avian Influenza Weekly Update Number 843 | 3 Human infection with avian influenza A(H9N2) virus Between 29 April 2022 and 5 May 2022, no new cases of human infection with avian influenza A(H9N2) were reported to WHO in the Western Pacific Region. To date, a total of 74 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. Human infection with avian influenza A(H10N3) virus Between 29 April 2022 and 5 May 2022, no new cases of human infection with avian influenza A(H10N3) virus were reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low. Animal infection with avian influenza virus Between 29 April 2022 and 5 May 2022, no new report of outbreaks of avian influenza among birds were reported to OIE from the Western Pacific Region. For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2022 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2022-2023 northern hemisphere influenza season (who.int) 25 February 2022 Avian Influenza Weekly Update Number 843 | 4 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2022-23 Northern Hemisphere Influenza Season 25 February 2022 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 844 13 May 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 6 May 2022 and 12 May 2022, no new case of human infection with avian influenza A(H5N1) virus was reported to WHO in the Western Pacific Region. As of 12 May 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 21 April 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 12 May 2022, there have been 864 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 864 cases, 456 were fatal (CFR of 53%). The latest case was reported from United States of America in April 2022. Human infection with avian influenza A(H5N6) virus Between 6 May 2022 and 12 May 2022, no new case of human infection with avian influenza A(H5N6) virus was notified to WHO in the Western Pacific Region. To date, a total of 78 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 32 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Avian Influenza Weekly Update Number 844 | 2 Human infection with avian influenza A(H3N8) virus Between 6 May 2022 and 12 May 2022, no new case of human infection with avian influenza A(H3N8) virus was reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H3N8) virus has been reported to WHO in the Western Pacific Region. This case was reported from China on 25 April 2022. Human infection with avian influenza A(H7N4) virus in China Between 6 May 2022 and 12 May 2022, no new case of human infection with avian influenza A(H7N4) virus was reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 6 May 2022 and 12 May, no new case of human infection with avian influenza A(H7N9) virus was reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was in 2019. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus. WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighboring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behavior to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 6 May 2022 and 12 May 2022, no new case of human infection with avian influenza A(H9N2) was reported to WHO in the Western Pacific Region. To date, a total of 74 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. Avian Influenza Weekly Update Number 844 | 3 Human infection with avian influenza A(H10N3) virus Between 6 May 2022 and 12 May, no new case of human infection with avian influenza A(H10N3) virus was reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low. Animal infection with avian influenza virus Between 6 May 2022 and 12 May, four reports of outbreaks of avian influenza among birds were reported to OIE from the Western Pacific Region. On 6 May 2022, the Philippines reported to OIE about highly pathogenic avian influenza A(H5N1) in one case of red breasted goose leading to one death in Jersey in Trinity. On 9 May 2022, the Philippines reported to OIE four outbreaks of highly pathogenic avian influenza A(H5N1) among poultry in Ampatuan in Maguindanao, M’Lang in North Cotabato, Santo Nino in South Cotabato, Magasasay in Davao del Sur. In total, there were 19 cases leading to 120 deaths. On 9 May 2022, the Philippines reported to OIE four outbreak of highly pathogenic avian influenza A(H5N1) among poultry in Talugtug, General Mamerto Natividad in Nueva Ecija Province. In total, there were 200 cases leading to 2,735 deaths. On 12 May 2022, the Chinese Taipei reported to OIE about one outbreak of highly pathogenic avian influenza A(H5N2) among poultry in Wanhua District of Taipei Province. In total, there was 1 case leading to 0 death among 11 susceptible cases. For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 1 October 2021 o Risk assessment summary: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Human infections with viruses of animal origin are expected at the human-animal interface wherever these viruses circulate in animals. • Recommended composition of influenza virus vaccines for use in the 2022 southern hemisphere influenza season (who.int) 24 September 2021 Avian Influenza Weekly Update Number 844 | 4 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2022-2023 northern hemisphere influenza season (who.int) 25 February 2022 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2022-23 Northern Hemisphere Influenza Season 25 February 2022 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.
Avian Influenza Weekly Update Number 845 20 May 2022 Human infection with avian influenza A(H5) viruses Human infection with avian influenza A(H5N1) virus Between 13 May 2022 and 19 May 2022, no new case of human infection with avian influenza A(H5N1) virus was reported to WHO in the Western Pacific Region. As of 12 May 2022, a total of 239 cases of human infection with avian influenza A(H5N1) virus have been reported from four countries within the Western Pacific Region since January 2003 (Table 1). Of these cases, 134 were fatal, resulting in a case fatality rate (CFR) of 56%. The last case was reported from Lao PDR, with an onset date of 13 October 2020 (one case, no death). Table 1: Cumulative number of laboratory-confirmed human cases (C) and deaths (D) of influenza A(H5N1) virus infection reported to WHO, by date of onset (January 2003 to 21 April 2022), Western Pacific Region Country 2003- 2009 2010- 2014 2015 2016 2017 2018 2019 2020 2021 2022 Total C D C D C D C D C D C D C D C D C D C D C D Cambodia 9 7 47 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 37 China 38 25 9 5 6 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 31 Lao PDR 2 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 2 Viet Nam 112 57 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 64 Total 161 91 71 42 6 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 239 134 Globally, from January 2003 to 12 May 2022, there have been 864 cases of human infection with avian influenza A(H5N1) virus reported from 18 countries. Of these 864 cases, 456 were fatal (CFR of 53%). The latest case was reported from United States of America in April 2022. Human infection with avian influenza A(H5N6) virus Between 13 May 2022 and 19 May 2022, no new case of human infection with avian influenza A(H5N6) virus was notified to WHO in the Western Pacific Region. To date, a total of 78 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 32 deaths have been reported to WHO in the Western Pacific Region since 2014. Public health risk assessment for human infection with avian influenza A(H5) viruses Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. The rise in numbers of reported human cases of A(H5N6) infection may reflect the continued circulation of the virus in birds, and enhanced surveillance system and diagnostic capacity as a direct outcome from the response to the COVID-19 pandemic. The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years. WHO recommends Member States to remain vigilant and consider mitigation steps to reduce human exposure to potentially infected birds to reduce risk of additional zoonotic infection. For information on risk assessments on Avian Influenza, visit: https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment- summary Assessment of risk associated with highly pathogenic avian influenza A(H5N6) virus Avian Influenza Weekly Update Number 845| 2 Human infection with avian influenza A(H3N8) virus Between 13 May 2022 and 19 May 2022, no new case of human infection with avian influenza A(H3N8) virus was reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed cases of human infection with influenza A(H3N8) virus has been reported to WHO in the Western Pacific Region. This case was reported from China on 25 April 2022. Human infection with avian influenza A(H7N4) virus in China Between 13 May 2022 and 19 May 2022, no new case of human infection with avian influenza A(H7N4) virus was reported to WHO in the Western Pacific Region. To date, only one laboratory-confirmed case of human infection with influenza A(H7N4) virus has been reported to WHO. This case was reported from China on 14 February 2018. Human infection with avian influenza A(H7N9) virus in China Between 13 May 2022 and 19 May, no new case of human infection with avian influenza A(H7N9) virus was reported to WHO in the Western Pacific Region. To date, a total of 1,568 laboratory-confirmed human infections with avian influenza A(H7N9) virus including 616 fatal cases (CFR: 39%) have been reported to WHO since early 2013. The last case of human infection with avian influenza A(H7N9) reported to WHO in the Western Pacific Region was in 2019. Of the 1,568 human infections with avian influenza A(H7N9), 33 have reported mutations in the hemagglutinin gene indicating a change to high pathogenicity in poultry. These 33 cases were from Taiwan, China (one case had travel history to Guangdong), Guangxi, Guangdong, Hunan, Shaanxi, Hebei, Henan, Fujian, Yunnan, and Inner Mongolia. No increased transmissibility or virulence of the virus within human cases has been detected related to the HPAI A(H7N9) virus. WHO is continuing to assess the epidemiological situation and will conduct further risk assessments as new information becomes available. The number and geographical distribution of human infections with avian influenza A(H7N9) viruses in the fifth epidemic wave (1 October 2016 to 30 September 2017) were greater than previous waves and the subsequent waves. Further sporadic human cases of avian influenza A(H7N9) virus infection are expected in affected and possibly neighboring areas. Should human cases from affected areas travel internationally, their infection may be detected in another country during or after arrival. However, if this were to occur, community level spread is considered unlikely as the virus does not have the ability to transmit easily among humans. To date, there is no evidence of sustained human-to-human transmission of avian influenza A(H7N9) virus. Human infections with the A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and transmission behavior to humans as this may have serious public health impacts. Human infection with avian influenza A(H9N2) virus Between 13 May 2022 and 19 May 2022, no new case of human infection with avian influenza A(H9N2) was reported to WHO in the Western Pacific Region. To date, a total of 74 cases of human infection with avian influenza A(H9N2) including two deaths (both with underlying conditions) have been reported to WHO in the Western Pacific Region since December 2015. Avian Influenza Weekly Update Number 845| 3 Human infection with avian influenza A(H10N3) virus Between 13 May 2022 and 19 May, no new case of human infection with avian influenza A(H10N3) virus was reported to WHO in the Western Pacific Region. To date, one case of avian influenza A(H10N3) virus has been reported globally. Most previously reported human infections with avian influenza viruses were due to exposure to infected poultry or contaminated environments. Since avian influenza viruses, including avian influenza A(H10N3) viruses, continue to be detected in poultry populations, further sporadic human cases could be detected in the future. Currently available epidemiologic information suggests that the avian influenza A(H10N3) virus has not acquired the ability for sustained human-to-human transmission, thus the likelihood of spread among human is low. Animal infection with avian influenza virus Between 13 May 2022 and 19 May, two reports of outbreaks of avian influenza among birds were reported to OIE from the Western Pacific Region. On 16 May 2022, Japan reported to OIE about highly pathogenic avian influenza A(H5N1) among poultry in Ichinoseki City. In total, there were 3 cases with 2 deaths, and the remaining 10 susceptible birds were killed and disposed. On 18 May 2022, Japan reported to OIE about highly pathogenic avian influenza A(H5N1) among poultry in Abashiri City in Hokkaido Perfecture and Daisen City in Akita Perfecture. In total, there were 14 cases with 2 death, and the remaining 758 susceptible birds were killed and disposed. For more information on animal infection with avian influenza viruses with potential public health impact, visit: • World Organization for Animal Health (OIE) web page: Weekly disease information and Latest report on Avian Influenza • Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza • Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES) • FAO Global Animal Disease Information System (EMPRES-i) Other updates • Influenza at the human-animal interface summary and assessment, 13 May 2022 • Recommended composition of influenza virus vaccines for use in the 2022 southern hemisphere influenza season (who.int) 24 September 2021 • WHO SAGE Seasonal Influenza Vaccination Recommendations during the COVID-19 Pandemic Interim guidance. 20 September 2020 • Recommended composition of influenza virus vaccines for use in the 2022-2023 northern hemisphere influenza season (who.int) 25 February 2022 • WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the 2022 Southern Hemisphere Influenza Season 13 – 30 September 2021 • WHO Information Meeting on the Composition of Influenza Virus Vaccines for Use in the 2022-23 Northern Hemisphere Influenza Season 25 February 2022 • Zoonotic influenza: candidate vaccine viruses and potency testing reagents.