Bi-weekly Influenza Situation Update 1 January 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 and week 51 are presented in the table below. Influenza A and B are cocirculating in the region, with influenza A (H3) and influenza B (Victoria lineage) showing increasing trend in levels of activity in recent weeks (Figure 1). Table 1: Cumulative data reported to FluNet from Western Pacific Region, weeks 1 to 51, 2019 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, weeks 1 to 51, 2019 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (51) 90851 13934 Cambodia (50) 1147 302 China (51) 695775 114731 Fiji (50) 496 185 Japan (50) 0 7763 Lao People's Democratic Republic (51) 3823 570 Malaysia (48) 4326 919 Mongolia (49) 3531 754 New Caledonia (45) 2160 540 New Zealand (33) 1963 957 Papua New Guinea (45) 134 19 Philippines (51) 1449 346 Republic of Korea (51) 11815 1584 Singapore (49) 3276 511 Viet Nam (46) 1478 327 Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, influenza activity is within normal seasonal trends observed during the corresponding period from previous years. Outpatient ILI Surveillance China (North) During week 51, the percentage of visits for ILI at national sentinel hospitals in Northern China was 5.3%, higher than the last week (4.7%), higher than the same week of 2016-2018 (3.5%, 5.2% and 3.7%) (Figure 2). Mongolia During week 51 ILI activity in Mongolia was higher than the previous week and became above the seasonal trend (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2016-2020 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2017-2019 (Source: Mongolia National Influenza Center) Influenza Situation Update | 3 Republic of Korea In week 51, the overall weekly ILI rate was 37.8 ILI cases per 1,000 outpatient visits, higher than the previous week with 28.5 ILI cases per 1,000 outpatient visits, following trends seen in previous years (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 consultations, Republic of Korea, 2014-2019 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 50 of 2019, influenza sentinel hospital activity is increasing in Japan and higher than the same period in recent years (Figure 5). Figure 5: Number of influenza cases reported weekly per reportingsentinel hospital site, Japan 2009-2019 (Source: Japan National Institute of Infectious Diseases) IL I/ 1 0 0 0 o u tp at ie n t Influenza Situation Update | 4 Countries/areas in the tropical zone Countries and areas in the tropical zone are generally observing influenza activity that is consistent with previous seasons. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 51, the average consultation rate for ILI among sentinel general outpatient clinics was 3.4 ILI cases per 1,000 consultations, which was lower than 4.2 ILI cases per 1,000 consultations recorded in the previous week and within expected seasonal levels compared to previous years (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 28.0 ILI cases per 1,000 consultations, which was higher than 26.4 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2015-2019 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2015-2019 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 51, the percentage of visits for ILI at national sentinel hospitals in Southern China was 5.6%, higher the previous week (5.3%), higher than the same week of 2016-2018 (3.3%, 4.3% and 3.8%). (Figure 8) Singapore – Acute Respiratory Infection (ARI) Surveillance In week 51, the average daily number of patients seeking treatment in the polyclinics for ARI was 3,050 over 5.5 working days, which is slightly lower than the previous week (30,62 over 5.5 working days). (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2016-2019 (Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2018-2019 (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR In week 51, the number of ILI cases presenting to sentinel sites was lower compared to the previous week and is within trends seen in past years. (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2015-2019, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May. Influenza activity increased unusually early in Australia however there are indications that activity is now decreasing. Australia – Laboratory-confirmed influenza and ILI (No update) In week 40, there were 3.9 ILI per 1,000 consultations at sentinel general practitioners, decreasing from the seasonal high of 13.3 per 1,000 consultations in week 28 and lower than the 5 year average for this time of year. There have been 298,120 laboratory-confirmed cases of influenza reported to the National Notifiable Diseases Surveillance System. While number of cases was slightly lower than the five year average, there has been a marked decrease in notifications per week following a peak in week 27 and now showing a weekly trend similar to that seen in past years. (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness (No update) There were 4 general practice visits for Influenza-like Illness per every 100,000 registered patients followed in New Zealand during the week ending 29 September. General Practice visits for influenza-like illness are well below the baseline level in the week ending 29 September, with a decrease compared to the previous week. (Figure 12). Figure 12: Weekly General Practice ILI Rates in New Zealand (Source: Institute of Environmental Science and Research Ltd (ESR), New Zealand) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 50 the number of ILI cases reported increased in several PICs, including Samoa, RMI, Solomon Island and Mariana Islands. (Figure 13). Influenza Situation Update | 7 Figure 13: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 15 January 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 3 2019 and week 1 2020 are presented in the table below. Influenza A and B are cocirculating in the region, with influenza A (H3) predominating but influenza B (Victoria lineage) increasing with a slight decrease in levels of activity in recent weeks (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 3 2019 to week 1 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 3 2019 to week 1 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (1) 91995 13827 Cambodia (52) 1153 305 China (1) 694069 115385 Fiji (50) 496 185 Japan (51) - 7101 Lao People's Democratic Republic (1) 3826 582 Malaysia (50) 4369 988 Mongolia (52) 3660 720 New Caledonia (52) 2204 538 New Zealand (33) 1963 957 Papua New Guinea (45) 131 18 Philippines (51) 1411 320 Republic of Korea (52) 11623 1500 Singapore (52) 3451 1108 Viet Nam (51) 1610 354 Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity increased slightly earlier than in previous seasons in China and Japan. Outpatient ILI Surveillance China (North) During week 1 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 5.9%, higher than the last week (5.5%) and the same week of 2016-2019 (3.8%, 5.7% and 5.3%) (Figure 2). Mongolia During week 1 2020, ILI activity in Mongolia was lower than the previous week and was back below the upper tolerance limits following a peak at the end of 2019 (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2016-2020 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2017-2020(Source: Mongolia National Influenza Center) Republic of Korea In week 1 2020, the overall weekly ILI rate was 49.1 ILI cases per 1,000 outpatient visits, slightly lower than the previous week with 49.8 ILI cases per 1,000 outpatient visits, lower than rates seen during the same week of previous years (Figure 4). Influenza Situation Update | 3 Figure 4: Weekly ILI incidence rate per 1,000 consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 51 of 2019, influenza sentinel hospital activity is increasing in Japan and higher than in the same period in recent years. Influenza activity increased slightly earlier than in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2009-2019 (Source: Japan National Institute of Infectious Diseases) IL I/ 1 0 0 0 o u tp at ie n t Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to increase in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 1 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 4.1 ILI cases per 1,000 consultations, which was higher than 3.2 ILI cases per 1,000 consultations recorded in the previous week and similar with last year (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 28.7 ILI cases per 1,000 consultations, which was lower than 29.1 recorded in the previous week and lower than previous years (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 1 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 6.6%, higher than the previous week (5.3%) and the same week of 2016-2019 (3.3%, 6.0% and 4.9%). ILI activity increased slightly earlier and to a higher level compared with previous seasons (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 1 2020, the average daily number of patients seeking treatment in the polyclinics for ARI was 3,842 over 4 working days, which is slightly higher than the previous week (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2016-2020 (Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR In week 1 2020, the number of ILI cases presenting to sentinel sites was higher compared to the previous week (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May. Currently influenza activity remained at low inter-seasonal levels. Australia – Laboratory-confirmed influenza and ILI (No update) In week 40, there were 3.9 ILI per 1,000 consultations at sentinel general practitioners, decreasing from the seasonal high of 13.3 per 1,000 consultations in week 28 and lower than the 5 year average for this time of year. There have been 298,120 laboratory-confirmed cases of influenza reported to the National Notifiable Diseases Surveillance System. While number of cases was slightly lower than the five year average, there has been a marked decrease in notifications per week following a peak in week 27 and now showing a weekly trend similar to that seen in past years (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness (No update) There were 4 general practice visits for Influenza-like Illness per every 100,000 registered patients followed in New Zealand during the week ending 29 September. General Practice visits for influenza-like illness are well below the baseline level in the week ending 29 September, with a decrease compared to the previous week (Figure 12). Figure 12: Weekly General Practice ILI Rates in New Zealand (Source: Institute of Environmental Science and Research Ltd (ESR), New Zealand) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 1 2020, the number of ILI cases reported increased in several PICs, including in Cook Islands, French Polynesia, Kiribati, New Caledonia, and Palau (Figure 13). Influenza Situation Update | 7 Figure 13: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 29 January 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 5 2019 and week 3 2020 are presented in the table below. Influenza A and B are cocirculating in the region, with influenza A (H3) predominating (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 5 2019 to week 3 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 5 2019 to week 3 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (3) 93,294 13,746 Cambodia (2) 1,153 304 China (2) 673,263 105,503 Fiji (50, 2019) 496 185 Japan (2) - 6,066 Lao People's Democratic Republic (3) 3,819 575 Malaysia (2) 4,569 1,098 Mongolia (3) 3,565 616 New Caledonia (52, 2019) 2,185 537 New Zealand (33, 2019) 1,963 957 Papua New Guinea (45, 2019) 122 15 Philippines (51, 2019) 1,347 291 Republic of Korea (2) 11,373 1,491 Singapore (52,2019) 3,305 1,047 Viet Nam (51,2019) 1,551 348 Influenza Situation Update| 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity increased slightly earlier than in previous seasons in China and Japan. Outpatient ILI Surveillance China (North) During week 3 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 4.5%, lower than the last week (5.2%), and higher than the same week of 2016-2017 (3.4%), and lower than the same week of 2018-2019 (5.2% and 5.4%) (Figure 2). Mongolia During week 4 2020, ILI activity in Mongolia was higher than the previous week and was above the upper tolerance limits (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2016-2020 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2017-2020 (Source: Mongolia National Influenza Center) Influenza Situation Update| 3 Republic of Korea In week 3 2020, the overall weekly ILI rate was 42.4 ILI cases per 1,000 outpatient visits, slightly lower than the previous week with 47.8 ILI cases per 1,000 outpatient visits. The peak this year is lower than 2016-2019, but the general trend was similar to that seen in previous seasons (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 2 of 2020, influenza sentinel hospital activity is increasing in Japan and within seasonally expected levels. (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2009-2019 (Source: Japan National Institute of Infectious Diseases) IL I/ 1 0 0 0 o u tp at ie n t Influenza Situation Update| 4 Countries/areas in the tropical zone ILI and influenza activity continued to increase in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 3 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 5.7 ILI cases per 1,000 consultations, which was lower than 6.1 ILI cases per 1,000 consultations recorded in the previous week and lower than the same week of previousyear (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 34.8 ILI cases per 1,000 consultations, which was lower than 39.0 recorded in the previous week and lower than previous years, 2016 - 2019 (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 3 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 5.1%, lower than the previous week (6.0%), higher than the same week of 2017 (2.8%), and lower than the same week of 2018 and 2019 (6.5% and 6.0% respectively). ILI activity increased slightly earlier compared with previous seasons (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 2 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 3,585 over 5.5 working days, which is slightly lower than the previous week but higher then the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2016-2020 (Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: Singapore Ministry of Health) Influenza Situation Update| 5 Lao PDR In week 2 2020, the number of ILI cases presenting to sentinel sites was slightly increased compared to the previous week and slightly higher than the same period of previous year (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May. Australia – Laboratory-confirmed influenza and ILI (No update) In week 40, there were 3.9 ILI per 1,000 consultations at sentinel general practitioners, decreasing from the seasonal high of 13.3 per 1,000 consultations in week 28 and lower than the 5 year average for this time of year. There have been 298,120 laboratory-confirmed cases of influenza reported to the National Notifiable Diseases Surveillance System. While number of cases was slightly lower than the five year average, there has been a marked decrease in notifications per week following a peak in week 27 and now showing a weekly trend similar to that seen in past years (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update| 6 New Zealand – Influenza like Illness (No update) There were 4 general practice visits for Influenza-like Illness per every 100,000 registered patients followed in New Zealand during the week ending 29 September. General Practice visits for influenza-like illness are well below the baseline level in the week ending 29 September, with a decrease compared to the previous week (Figure 12). Figure 12: Weekly General Practice ILI Rates in New Zealand (Source: Institute of Environmental Science and Research Ltd (ESR), New Zealand) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 3 2020, the number of ILI cases reported increased in several PICs, including in Cook Islands, French Polynesia, Pitcairn Islands, Solomon Islands, Tonga, and Vanustu (Figure 13). Influenza Situation Update| 7 Figure 13: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 12 February 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 2020 and week 5 2020 are presented in the table below. Influenza A and B are cocirculating in the region, with influenza A (H3) predominating however in recent weeks the proportion of A(H3) reported has increased (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 5 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 7 2019 to week 6 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (5) 3,619 238 Cambodia (5) 122 26 China (4) 45,157 13,364 Fiji (4) 24 2 Japan (4) - 230 Lao People's Democratic Republic (3) 208 59 Malaysia (2) 202 54 Mongolia (3) 674 245 New Caledonia - - New Zealand - - Papua New Guinea - - Philippines (4) 92 8 Republic of Korea (2) 290 126 Singapore - - Viet Nam - - Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity increased slightly earlier than in previous seasons in China and Japan. Outpatient ILI Surveillance China (North) During week 5 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 8.5%, higher than the last week (6.8%), and higher than the same week of 2017-2019 (3.6%, 4.2% and 4.5%) (Figure 2). Mongolia During week 5 2020, ILI activity in Mongolia was lower than the previous week and remained above the upper tolerance limits (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2016-2020 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2017-2020 (Source: Mongolia National Influenza Center) Influenza Situation Update | 3 Republic of Korea In week 5 2020, the overall weekly ILI rate was 28.0 ILI cases per 1,000 outpatient visits, slightly lower than the previous week with 40.9 ILI cases per 1,000 outpatient visits. The peak this year is lower than 2016-2019 (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 3 of 2020, influenza sentinel hospital activity in Japan was lower than the previous week and is lower than previously reported seasonal levels (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) IL I/ 1 0 0 0 o u tp at ie n t Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to increase in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 5 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 4.5 ILI cases per 1,000 consultations, which was lower than 6.7 ILI cases per 1,000 consultations recorded in the previous week and lower than the same week of the previous year (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 20.5 ILI cases per 1,000 consultations, which was higher than 15.5 recorded in the previous week and lower than previous years, 2016 - 2019 (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 5 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 8.0%, higher than the previous week (7.4%), higher than the same week of 2017-2019 (3.5%, 5.1%, and 5.1%). ILI activity increased slightly earlier compared with previous seasons (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 5 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 4,728 over 4.5 working days, which is higher than the previous week and the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2016-2020 (Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR (No update) In week 2 2020, the number of ILI cases presenting to sentinel sites was slightly increased compared to the previous week and slightly higher than the same period of previous year (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI (No update) In week 40, there were 3.9 ILI per 1,000 consultations at sentinel general practitioners, decreasing from the seasonal high of 13.3 per 1,000 consultations in week 28 and lower than the 5 year average for this time of year. There have been 298,120 laboratory-confirmed cases of influenza reported to the National Notifiable Diseases Surveillance System. While number of cases was slightly lower than the five year average, there has been a marked decrease in notifications per week following a peak in week 27 and now showing a weekly trend similar to that seen in past years (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness (No update) There were 4 general practice visits for Influenza-like Illness per every 100,000 registered patients followed in New Zealand during the week ending 29 September. General Practice visits for influenza-like illness are well below the baseline level in the week ending 29 September, with a decrease compared to the previous week (Figure 12). Figure 12: Weekly General Practice ILI Rates in New Zealand (Source: Institute of Environmental Science and Research Ltd (ESR), New Zealand) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 5 2020, the number of ILI cases reported increased in several PICs, including in Cook Islands, Fiji, and Vanuatu (Figure 13). Influenza Situation Update | 7 Figure 13: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 26 February 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 2020 and week 7 2020 are presented in the table below. Influenza A and B are cocirculating in the region, with influenza A (H3) predominating (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 7 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 9 2019 to week 7 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (7) 4,715 283 Cambodia (7) 170 36 China (7) 99,404 27,792 Fiji (4) 24 2 Japan (6) - 520 Lao People's Democratic Republic (7) 594 145 Malaysia (6) 377 111 Mongolia (7) 2,221 929 New Caledonia (6) 75 15 New Zealand - - Papua New Guinea - - Philippines (4) 92 8 Republic of Korea (6) 1,409 505 Singapore - - Viet Nam - - Influenza Situation Update| 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity increased slightly earlier than in previous seasons in China and Japan. Outpatient ILI Surveillance China (North) During week 7 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 5.4%, lower than the last week (6.2%), and higher than the same week of 2017-2019 (2.7%, 44.5% and 3.4%) (Figure 2). Mongolia During week 7 2020, ILI activity in Mongolia has significantly decreased compare to last week and below the lower tolerance limit (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2016-2020 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Influenza Situation Update| 3 Republic of Korea In week 7 2020, the overall weekly ILI rate was 11.6 ILI cases per 1,000 outpatient visits, slightly lower than the previous week with 16.4 ILI cases per 1,000 outpatient visits. The peak this year is lower than 2016-2019, but the general trend was similar to that seen in previous seasons (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 6 of 2020, influenza sentinel hospital activity in Japan was lower than the previous week and within seasonally expected levels (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) IL I/ 1 0 0 0 o u tp at ie n t Influenza Situation Update| 4 Countries/areas in the tropical zone ILI and influenza activity continued to increase in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 7 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 1.9 ILI cases per 1,000 consultations, which was lower than 2.1 ILI cases per 1,000 consultations recorded in the previous week and significantly lower than the same week of the previous year (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 30.2 ILI cases per 1,000 consultations, which was higher than 29.1 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 7 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 4.6%, lower than the previous week and the same week of 2018 (5.8% and 5.9%), higher than the same week of 2017 and 2019 (2.7%, and 4.1%). ILI activity increased slightly earlier compared with previous seasons, but the general trend was similar to that seen in previous seasons (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 7 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 3,150 over 5.5 working days, which is slightly lower than the previous week and the same time period in 2019 (Figure 9). Influenza Situation Update| 5 Lao PDR In week 7 2020, the number of ILI cases presenting to sentinel sites was slightly increased compared to the previous week and slightly higher than the same period of previous year (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI (No update) In week 40, there were 3.9 ILI per 1,000 consultations at sentinel general practitioners, decreasing from the seasonal high of 13.3 per 1,000 consultations in week 28 and lower than the 5 year average for this time of year. There have been 298,120 laboratory-confirmed cases of influenza reported to the National Notifiable Diseases Surveillance System. While number of cases was slightly lower than the five year average, there has been a marked decrease in notifications per week following a peak in week 27 and now showing a weekly trend similar to that seen in past years (Figure 11). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2016-2020 (Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: Singapore Ministry of Health) Influenza Situation Update| 6 Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) New Zealand – Influenza like Illness (No update) There were 4 general practice visits for Influenza-like Illness per every 100,000 registered patients followed in New Zealand during the week ending 29 September. General Practice visits for influenza-like illness are well below the baseline level in the week ending 29 September, with a decrease compared to the previous week (Figure 12). Figure 12: Weekly General Practice ILI Rates in New Zealand (Source: Institute of Environmental Science and Research Ltd (ESR), New Zealand) Influenza Situation Update| 7 Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 7 2020, the number of ILI cases reported increased in several PICs, including in Federated States of Micronesia, Fiji and Vanuatu (Figure 13). Figure 13: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Influenza Situation Update| 8 Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 11 March 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 2020 and week 9 2020 are presented in the table below. Influenza A and B are cocirculating in the region, with influenza A(H3) predominating (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 7 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 11 2019 to week 9 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (9) 11,164 619 Cambodia (7) 170 36 China (8) 122,895 30,080 Fiji (8) 79 9 Japan (8) - 1,024 Lao People's Democratic Republic (8) 652 153 Malaysia (7) 642 211 Mongolia (7) 2,221 929 New Caledonia (6) 75 15 New Zealand - - Papua New Guinea - - Philippines (4) 92 8 Republic of Korea (6) 1,409 505 Singapore (8) 1,026 353 Viet Nam - - Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity increased slightly earlier than in previous seasons in China and Japan. Outpatient ILI Surveillance China (North) During week 9 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 3.5% lower than the last week (4.4%), and higher than the same week of 2017-2019 (2.7%, 2.9% and 2.8%) (Figure 2). Mongolia During week 9 2020, ILI activity in Mongolia has a decrease trend and below the lower tolerance limit (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2016-2020 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Influenza Situation Update | 3 Republic of Korea In week 9 2020, the overall weekly ILI rate was 6.3 ILI cases per 1,000 outpatient visits, slightly lower than the previous week with 8.5 ILI cases per 1,000 outpatient visits. The peak this year is lower than 2016-2019, but the general trend was similar to that seen in previous seasons (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 8 of 2020, influenza sentinel hospital activity in Japan has a decrease trend and within seasonally expected levels (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) IL I/1 00 0 ou tp at ie nt Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to increase in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 9 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 1.7 ILI cases per 1,000 consultations, which was higher than 1.2 ILI cases per 1,000 consultations recorded in the previous week but significantly lower than the same week of the previous year (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 27.5 ILI cases per 1,000 consultations, which was higher than 26.6 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 9 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 3.3%, lower than the previous week (3.7%), higher than the same week of 2017 (3.0%), lower than the same week of 2018 and 2019 (both 4.0%). ILI activity increased slightly earlier compared with previous seasons, but the general trend was similar to that seen in previous seasons (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 9 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 2,473 over 5.5 working days, which is slightly lower than the previous week and the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2016-2020 (Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR In week 9 2020, the number of ILI cases presenting to sentinel sites was slightly increased compared to the previous week and higher than the same period of previous year (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI (No update) In week 40, there were 3.9 ILI per 1,000 consultations at sentinel general practitioners, decreasing from the seasonal high of 13.3 per 1,000 consultations in week 28 and lower than the 5 year average for this time of year. There have been 298,120 laboratory-confirmed cases of influenza reported to the National Notifiable Diseases Surveillance System. While number of cases was slightly lower than the five year average, there has been a marked decrease in notifications per week following a peak in week 27 and now showing a weekly trend similar to that seen in past years (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness (No update) There were 4 general practice visits for Influenza-like Illness per every 100,000 registered patients followed in New Zealand during the week ending 29 September. General Practice visits for influenza-like illness are well below the baseline level in the week ending 29 September, with a decrease compared to the previous week (Figure 12). Figure 12: Weekly General Practice ILI Rates in New Zealand (Source: Institute of Environmental Science and Research Ltd (ESR), New Zealand) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 9 2020, the number of ILI cases reported increased in several PICs, including in Cook Island, Fiji and Vanuatu (Figure 13). Influenza Situation Update | 7 Figure 13: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Influenza Situation Update | 8 Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 25 March 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 2020 and week 9 2020 are presented in the table below. Influenza A and B are cocirculating in the region, with influenza A (H3) predominating (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 7 2020 (no update) Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 11 2019 to week 9 2020 (Source: WHO FLUNET) no update Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (9) 11,164 619 Cambodia (7) 170 36 China (8) 122,895 30,080 Fiji (8) 79 9 Japan (8) - 1,024 Lao People's Democratic Republic (8) 652 153 Malaysia (7) 642 211 Mongolia (7) 2,221 929 New Caledonia (6) 75 15 New Zealand - - Papua New Guinea - - Philippines (4) 92 8 Republic of Korea (6) 1,409 505 Singapore (8) 1,026 353 Viet Nam - - Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity continue to decrease, lower than in previous seasons. Outpatient ILI Surveillance China (North) During week 11 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 2.5%, lower than the last week (2.8%), and lower than the same week of 2017-2019 (2.8%, 2.6% and 3.3%) (Figure 2). ILI activity continues to disease after a peak during week 5. Mongolia During week 11 2020, ILI activity in Mongolia has a decrease trend and below the lower tolerance limit (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2016-2020 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Influenza Situation Update | 3 Republic of Korea In week 11 2020, the overall weekly ILI rate was 2.9 ILI cases per 1,000 outpatient visits, lower than the previous week with 3.9 ILI cases per 1,000 outpatient visits and below the national epidemic threshold (5.9 ILI cases per 1,000 outpatient visits) (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 10 of 2020, influenza sentinel hospital activity in Japan has a decrease trend and within seasonally expected levels. The peak this year is lower than the previous years, but the general trend was similar to that seen in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to decrease in China and Singapore, while increased in Lao PDR. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 11 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 1.3 ILI cases per 1,000 consultations, which was higher than 1.1 ILI cases per 1,000 consultations recorded in the previous week but significantly lower than the same week of the previous year (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 30.2 ILI cases per 1,000 consultations, which was higher than 24.1 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 11 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 2.8%, lower than the previous week (2.9%), lower than the same week of 2017-2019 (3.0%, 3.6% and 4.1%). ILI activity continues to decrease since week 5 (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 11 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 2,288 over 5.5 working days, which is lower than the previous weeks and the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2016-2020 (Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR In week 11 2020, the number of ILI cases presenting to sentinel sites was increased compared to the previous weeks and higher than the same period of previous year (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI (No update) In week 40, there were 3.9 ILI per 1,000 consultations at sentinel general practitioners, decreasing from the seasonal high of 13.3 per 1,000 consultations in week 28 and lower than the 5 year average for this time of year. There have been 298,120 laboratory-confirmed cases of influenza reported to the National Notifiable Diseases Surveillance System. While number of cases was slightly lower than the five year average, there has been a marked decrease in notifications per week following a peak in week 27 and now showing a weekly trend similar to that seen in past years (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness (No update) There were 4 general practice visits for Influenza-like Illness per every 100,000 registered patients followed in New Zealand during the week ending 29 September. General Practice visits for influenza-like illness are well below the baseline level in the week ending 29 September, with a decrease compared to the previous week (Figure 12). Figure 12: Weekly General Practice ILI Rates in New Zealand (Source: Institute of Environmental Science and Research Ltd (ESR), New Zealand) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 11 2020, the number of ILI cases reported increased in several PICs, including in Cook Islands, French Polynesia and Palau (Figure 13). Influenza Situation Update | 7 Figure 13: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 8 April 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 2020 and week 14 2020 are presented in the table below. Influenza A and B are cocirculating in the region, with influenza A (H3) predominating (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 14 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 15 2019 to week 14 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (14) 28309 926 Cambodia (14) 306 67 China (14) 178901 30759 Fiji (14) 79 9 Japan (14) - 1908 Lao People's Democratic Republic (14) 934 206 Malaysia (14) 1064 281 Mongolia (14) 3008 972 New Caledonia (14) 75 15 New Zealand - - Papua New Guinea - - Philippines (14) 92 8 Republic of Korea (14) 1409 505 Singapore (14) 1250 363 Viet Nam - - Influenza Situation Update| 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity continue to decrease, lower than in previous seasons. Outpatient ILI Surveillance China (North) During week 13 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 2.3%, lower than the last week (2.4%), and lower than the same week of 2017-2019 (2.7%, 2.6% and 3.6%) (Figure 2). ILI activity continues to disease after a peak in week 5. Mongolia During week 13 2020, ILI activity in Mongolia has a decrease trend and below the lower tolerance limit (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2016-2020 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Influenza Situation Update| 3 Republic of Korea In week 13 of 2020, the overall weekly ILI rate was 2.8 ILI cases per 1,000 outpatient visits, lower than the previous week with 3.2 ILI cases per 1,000 outpatient visits and below the national epidemic threshold (5.9 ILI cases per 1,000 outpatient visits) (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 12 of 2020, influenza sentinel hospital activity in Japan has a decrease trend. The peak this year is lower than the previous years, but the general trend was similar to that seen in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) Influenza Situation Update| 4 Countries/areas in the tropical zone ILI and influenza activity continued to decrease in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 13 of 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 1.2 ILI cases per 1,000 consultations, which was lower than 1.6 ILI cases per 1,000 consultations recorded in the previous week but significantly lower than the same week of the previous year (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 19.3 ILI cases per 1,000 consultations, which was lower than 20.5 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 13 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 2.4%, lower than the previous week (2.7%), lower than the same week of 2017-2019 (3.1%, 3.6% and 4.0%). ILI activity continues to decrease after a peak in week 5 (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 14 of 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 2,065 over 5.5 working days, which is lower than the previous weeks and the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2016- 2020(Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020(Source: Singapore Ministry of Health) Influenza Situation Update| 5 Lao PDR In week 13 of 2020, the number of ILI cases presenting to sentinel sites was decreased compared to the previous week but higher than the same period of previous year (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI (No update) In week 40, there were 3.9 ILI per 1,000 consultations at sentinel general practitioners, decreasing from the seasonal high of 13.3 per 1,000 consultations in week 28 and lower than the 5 year average for this time of year. There have been 298,120 laboratory-confirmed cases of influenza reported to the National Notifiable Diseases Surveillance System. While number of cases was slightly lower than the five year average, there has been a marked decrease in notifications per week following a peak in week 27 and now showing a weekly trend similar to that seen in past years (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update| 6 New Zealand – Influenza like Illness (No update) There were 4 general practice visits for Influenza-like Illness per every 100,000 registered patients followed in New Zealand during the week ending 29 September. General Practice visits for influenza-like illness are well below the baseline level in the week ending 29 September, with a decrease compared to the previous week (Figure 12). Figure 12: Weekly General Practice ILI Rates in New Zealand (Source: Institute of Environmental Science and Research Ltd (ESR), New Zealand) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 13 of 2020, the number of ILI cases reported increased in several PICs, including in Samoa and Tokelau (Figure 13). Influenza Situation Update| 7 Figure 13: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 22 April 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 (2020) and week 16 (2020) are presented in the table below. Influenza A and B are cocirculating in the region, at a very low level compared to previous year (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 16 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 15 2019 to week 16 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (14) 30747 933 Cambodia (14) 328 67 China (14) 202740 30885 Fiji (14) 79 9 Japan (14) - 1908 Lao People's Democratic Republic (14) 1030 208 Malaysia (14) 1064 281 Mongolia (14) 3008 972 New Caledonia (14) 75 15 New Zealand - - Papua New Guinea - - Philippines (14) 92 8 Republic of Korea (14) 1409 505 Singapore (14) 1250 363 Viet Nam - - Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity continue to decrease, lower than in previous seasons. Outpatient ILI Surveillance China (North) During week 15 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 1.9%, lower than the last week (2.4%), and lower than the same week of 2017-2019 (2.5%, 2.4% and 3.7%) (Figure 2). ILI activity continues to disease after a peak in week 5. Mongolia During week 13 2020, ILI activity in Mongolia has a decrease trend and below the lower tolerance limit (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2016-2020 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Republic of Korea In week 15 of 2020, the overall weekly ILI rate was 2.7 ILI cases per 1,000 outpatient visits, higher than the previous week with 2.5 ILI cases per 1,000 outpatient visits and below the national epidemic threshold (5.9 ILI cases per 1,000 outpatient visits) (Figure 4). Influenza Situation Update | 3 Figure 4: Weekly ILI incidence rate per 1,000 consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 14 of 2020, influenza sentinel hospital activity in Japan has a decrease trend. The peak this year is lower than the previous years, but the general trend was similar to that seen in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to decrease in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 15 of 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 0.9 ILI cases per 1,000 consultations, which was lower than 1.3 ILI cases per 1,000 consultations recorded in the previous week but significantly lower than the same week of the previous year (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 14.4 ILI cases per 1,000 consultations, which was higher than 12.1 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 15 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 2.3%, higher than the previous week (2.2%), lower than the same week of 2017-2019 (3.2%, 3.3% and 4.1%). ILI activity this season remains lower than previous seasons. (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 14 5of 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 1,558 over 4.5 working days, which is lower than the previous weeks and the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2016-2020 (Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR In week 15 of 2020, the number of ILI cases presenting to sentinel sites was decreased compared to the previous week and lower than the same period of previous years (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI (No update) In week 40, there were 3.9 ILI per 1,000 consultations at sentinel general practitioners, decreasing from the seasonal high of 13.3 per 1,000 consultations in week 28 and lower than the 5 year average for this time of year. There have been 298,120 laboratory-confirmed cases of influenza reported to the National Notifiable Diseases Surveillance System. While number of cases was slightly lower than the five year average, there has been a marked decrease in notifications per week following a peak in week 27 and now showing a weekly trend similar to that seen in past years (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness (No update) There were 4 general practice visits for Influenza-like Illness per every 100,000 registered patients followed in New Zealand during the week ending 29 September. General Practice visits for influenza-like illness are well below the baseline level in the week ending 29 September, with a decrease compared to the previous week (Figure 12). Figure 12: Weekly General Practice ILI Rates in New Zealand (Source: Institute of Environmental Science and Research Ltd (ESR), New Zealand) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 13 of 2020, the number of ILI cases reported increased in several PICs, including in Fiji and Samoa (Figure 13). Influenza Situation Update | 7 Figure 13: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 6 May 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 2020 and week 17 2020 are presented in the table below. Influenza A and B are cocirculating in the region, at a very low level compared to previous year (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 17 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 19 2019 to week 17 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (17) 36773 941 Cambodia (17) 328 67 China (17) 222698 30920 Fiji (17) 79 9 Japan (17) - 2154 Lao People's Democratic Republic (17) 1039 208 Malaysia (17) 1064 281 Mongolia (17) 4240 981 New Caledonia (17) 75 15 New Zealand - - Papua New Guinea - - Philippines (17) 92 8 Republic of Korea (17) 1409 505 Singapore (17) 1698 375 Viet Nam - - Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity continue to decrease, lower than in previous seasons. Outpatient ILI Surveillance China (North) During week 17 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 1.8%, lower than the last week (1.9%), and lower than the same week of 2017-2019 (2.5%, 2.3% and 3.2%) (Figure 2). ILI activity continues to disease after a peak in week 5. Mongolia During week 18 2020, ILI activity in Mongolia has a decrease trend and below the lower tolerance limit (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2016-2020 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Republic of Korea In week 17 of 2020, the overall weekly ILI rate was 2.4 ILI cases per 1,000 outpatient visits, higher than the previous week with 2.3 ILI cases per 1,000 outpatient visits and below the national epidemic threshold (5.9 ILI cases per 1,000 outpatient visits) (Figure 4). Influenza Situation Update | 3 Figure 4: Weekly ILI incidence rate per 1,000 outpatient consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 16 of 2020, influenza sentinel hospital activity in Japan has a decrease trend. The peak this year is lower than the previous years, but the general trend was similar to that seen in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to decrease in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 17 of 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 0.6 ILI cases per 1,000 consultations, which was lower than 1.0 ILI cases per 1,000 consultations recorded in the previous week and significantly lower than the same week of the previous year (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 20.6 ILI cases per 1,000 consultations, which was higher than 9.1 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 17 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 2.4%, same as the last week (2.4%), lower than the same week of 2017-2019 (3.1%, 3.6% and 4.2%). ILI activity this season remains lower than previous seasons. (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 16 5of 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 1,121 over 5.5 working days, which is lower than the previous weeks and the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2016-2020 (Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR In week 17 of 2020, the number of ILI cases presenting to sentinel sites was decreased compared to the previous week and lower than the same period of previous years (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI (No update) In week 40, there were 3.9 ILI per 1,000 consultations at sentinel general practitioners, decreasing from the seasonal high of 13.3 per 1,000 consultations in week 28 and lower than the 5 year average for this time of year. There have been 298,120 laboratory-confirmed cases of influenza reported to the National Notifiable Diseases Surveillance System. While number of cases was slightly lower than the five year average, there has been a marked decrease in notifications per week following a peak in week 27 and now showing a weekly trend similar to that seen in past years (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness (No update) There were 4 general practice visits for Influenza-like Illness per every 100,000 registered patients followed in New Zealand during the week ending 29 September. General Practice visits for influenza-like illness are well below the baseline level in the week ending 29 September, with a decrease compared to the previous week (Figure 12). Figure 12: Weekly General Practice ILI Rates in New Zealand (Source: Institute of Environmental Science and Research Ltd (ESR), New Zealand) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 17 of 2020, the number of ILI remains low (Figure 13). Influenza Situation Update | 7 Figure 13: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 20 May 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 2020 and week 19 2020 are presented in the table below. Influenza A and B are cocirculating in the region, at a very low level compared to previous year (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 19 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 19 2019 to week 19 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (19) 42316 942 Cambodia (19) 328 67 China (19) 237871 30926 Fiji (19) 79 9 Japan (19) -- 2254 Lao People's Democratic Republic (19) 1058 208 Malaysia (19) 1143 283 Mongolia (19) 4391 981 New Caledonia (19) 75 15 New Zealand - - Papua New Guinea - - Philippines (19) 92 8 Republic of Korea (19) 1409 505 Singapore (19) 1797 376 Viet Nam (19) 330 12 Influenza Situation Update| 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity continue to decrease, lower than in previous seasons. Outpatient ILI Surveillance China (North) During week 19 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 1.9%, same as the last week (1.9%), and lower than the same week of 2017-2019 (2.6%, 2.3% and 2.6%) (Figure 2). Mongolia During week 19 2020, ILI activity in Mongolia has a decrease trend and below the lower tolerance limit (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2016-2020 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Influenza Situation Update| 3 Republic of Korea In week 19 of 2020, the overall weekly ILI rate was 2.1 ILI cases per 1,000 outpatient visits, higher than the previous week with 1.7 ILI cases per 1,000 outpatient visits and below the national epidemic threshold (5.9 ILI cases per 1,000 outpatient visits) (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 outpatient consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 17 of 2020, influenza activity in Japan remains very low. The peak this year is lower than the previous years, but the general trend was similar to that seen in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) Influenza Situation Update| 4 Countries/areas in the tropical zone ILI and influenza activity continued to decrease in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 19 of 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 0.6 ILI cases per 1,000 consultations, which was the same as 0.6 ILI cases per 1,000 consultations recorded in the previous week and significantly lower than the same week of the previous year (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 15.8 ILI cases per 1,000 consultations, which was lower than 16.2 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 19 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 2.7%, higher than the last week (2.6%), lower than the same week of 2017-2019 (3.2%, 3.7% and 4.0%). ILI activity this season remains lower than previous seasons. (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 19 of 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 620 over 4.5 working days, which is lower than the previous weeks and the same time period in 2019 (Figure 9). Influenza Situation Update| 5 Lao PDR In week 18 of 2020, the number of ILI cases presenting to sentinel sites was decreased compared to the previous week and lower than the same period of previous years (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2016-2020 Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: China National Influenza Center) (Source: Singapore Ministry of Health) Influenza Situation Update| 6 Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI (No update) In week 40, there were 3.9 ILI per 1,000 consultations at sentinel general practitioners, decreasing from the seasonal high of 13.3 per 1,000 consultations in week 28 and lower than the 5 year average for this time of year. There have been 298,120 laboratory-confirmed cases of influenza reported to the National Notifiable Diseases Surveillance System. While number of cases was slightly lower than the five year average, there has been a marked decrease in notifications per week following a peak in week 27 and now showing a weekly trend similar to that seen in past years (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) New Zealand – Influenza like Illness (No update) There were 4 general practice visits for Influenza-like Illness per every 100,000 registered patients followed in New Zealand during the week ending 29 September. General Practice visits for influenza-like illness are well below the baseline level in the week ending 29 September, with a decrease compared to the previous week (Figure 12). Figure 12: Weekly General Practice ILI Rates in New Zealand (Source: Institute of Environmental Science and Research Ltd (ESR), New Zealand) Influenza Situation Update| 7 Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 19 of 2020, increases in the number of ILI cases were seen in Fiji, FSM, Kiribati and Wallis & Futuna (Figure 13). Figure 13: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Influenza Situation Update| 8 Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 3 June 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 2020 and week 21 2020 are presented in the table below. Influenza A and B are cocirculating in the region, at a very low level compared to previous year (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 21 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 23 2019 to week 22 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (21) 48269 942 Cambodia (21) 455 68 China (21) 254525 30937 Fiji (21) 79 9 Japan (21) - 2332 Lao People's Democratic Republic (21) 1058 208 Malaysia (21) 1143 283 Mongolia (21) 4502 981 New Caledonia (21) 75 15 New Zealand - - Papua New Guinea - - Philippines (21) 92 8 Republic of Korea (21) 1409 505 Singapore (21) 1831 376 Viet Nam - - Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity continue to decrease, lower than in previous seasons. Outpatient ILI Surveillance China (North) During week 21 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 1.9%, same as the last week (1.9%), and lower than the same week of 2017-2019 (2.4%, 2.3% and 2.5%) (Figure 2). ILI activity is plauteauing after a peak in week 5 of 2020. Mongolia During week 21 2020, ILI activity in Mongolia has a decrease trend and below the lower tolerance limit (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2016-2021 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Influenza Situation Update | 3 Republic of Korea In week 21 of 2020, the overall weekly ILI rate was 2.2 ILI cases per 1,000 outpatient visits, lower than the previous week with 2.3 ILI cases per 1,000 outpatient visits and below the national epidemic threshold (5.9 ILI cases per 1,000 outpatient visits) (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 outpatient consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 20 of 2020, influenza sentinel hospital activity in Japan has an increasing trend. The peak this year is lower than the previous years, but the general trend was similar to that seen in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to decrease in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 21 of 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 0.6 ILI cases per 1,000 consultations, which was lower than 0.7 ILI cases per 1,000 consultations recorded in the previous week and significantly lower than the same week of the previous year (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 13.1 ILI cases per 1,000 consultations, which was lower than 17.1 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 21 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 2.9%, higher than the last week (2.7%), lower than the same week of 2017-2019 (3.4%, 4.1% and 4.2%). ILI activity this season remains lower than previous seasons. (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 21 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 505 over 5.5 working days, which is lower than the previous weeks and the same time period in 2019 (Figure 9). Influenza Situation Update | 5 Lao PDR In week 21 of 2020, the number of ILI cases presenting to sentinel sites was decreased compared to previous week, but lower if compare to same week of previous year (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2016-2020 Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: China National Influenza Center) (Source: Singapore Ministry of Health) Influenza Situation Update | 6 Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI (No update) In week 40, there were 3.9 ILI per 1,000 consultations at sentinel general practitioners, decreasing from the seasonal high of 13.3 per 1,000 consultations in week 28 and lower than the 5 year average for this time of year. There have been 298,120 laboratory-confirmed cases of influenza reported to the National Notifiable Diseases Surveillance System. While number of cases was slightly lower than the five year average, there has been a marked decrease in notifications per week following a peak in week 27 and now showing a weekly trend similar to that seen in past years (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) New Zealand – Influenza like Illness (No update) There were 4 general practice visits for Influenza-like Illness per every 100,000 registered patients followed in New Zealand during the week ending 29 September. General Practice visits for influenza-like illness are well below the baseline level in the week ending 29 September, with a decrease compared to the previous week (Figure 12). Figure 12: Weekly General Practice ILI Rates in New Zealand (Source: Institute of Environmental Science and Research Ltd (ESR), New Zealand) Influenza Situation Update | 7 Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 21 of 2020, the number of ILI remains low (Figure 13). Figure 13: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Influenza Situation Update | 8 Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 1 July 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 and week 25 of 2020 are presented in the table below. Influenza A and B are cocirculating in the region, at a very low level compared to previous year (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 25 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 27 2019 to week 26 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (25) 53681 943 Cambodia (25) 539 68 China (24) 279333 30954 Fiji (8) 79 9 Japan (24) - 2466 Lao People's Democratic Republic (25) 1243 208 Malaysia (17) 1143 283 Mongolia (25) 4636 981 New Caledonia (6) 75 15 New Zealand - - Papua New Guinea - - Philippines (4) 92 8 Republic of Korea (6) 1409 505 Singapore (25) 1942 376 Viet Nam (22) 371 11 Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity continue to decrease, lower than in previous seasons. Outpatient ILI Surveillance China (North) During week 25 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 2.4%, higher than the last week (2.2%), and higher than the same week in 2019 (2.3%). This is the same as the same week in 2018 and lower than the same week in 2017, (2.4% and 2.5%) (Figure 2). Mongolia During week 23 2020, ILI activity in Mongolia has a decrease trend and similar to the lower tolerance limit (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2016-2021 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Influenza Situation Update | 3 Republic of Korea In week 25 of 2020, the overall weekly ILI rate was 2.0 ILI cases per 1,000 outpatient visits, same as the previous week with 2.0 ILI cases per 1,000 outpatient visits and below the national epidemic threshold (5.9 ILI cases per 1,000 outpatient visits) (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 outpatient consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 23 of 2020, influenza sentinel hospital activity in Japan plateaued. The peak this year is lower than the previous years, but the general trend was similar to that seen in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to decrease in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 25 of 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 0.7 ILI cases per 1,000 consultations, which was lower than 0.9 ILI cases per 1,000 consultations recorded in the previous week and significantly lower than the same week of the previous year (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 17.3 ILI cases per 1,000 consultations, which was higher than 13.6 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 25, 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 3.3%, same as last week (3.3%), lower than the same week of 2017-2019 (3.8%, 3.8% and 4.2%). ILI activity this season remains lower than previous seasons. (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 25 of 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 808 over 5.5 working days, which is significantly lower than the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2016-2020 (Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR The number of ILI cases presenting to sentinel sites has increased since week 19. In week 25 of 2020, it is similar to same week of previous years (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI From January to 14 June 2020, there have been 20,631 notifications of laboratory-confirmed influenza to the National Notifiable Diseases Surveillance System. Number of cases was lower than the five year average but showing a weekly trend similar to that seen in past years, except 2019 (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness (No update) There were 4 general practice visits for Influenza-like Illness per every 100,000 registered patients followed in New Zealand during the week ending 29 September. General Practice visits for influenza-like illness are well below the baseline level in the week ending 29 September, with a decrease compared to the previous week (Figure 12). Figure 12: Weekly General Practice ILI Rates in New Zealand (Source: Institute of Environmental Science and Research Ltd (ESR), New Zealand) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 22 of 2020, the number of ILI increased in Cook Islands, Samoa and Palau. (Figure 13). Influenza Situation Update | 7 Figure 13: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 15 July 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 and week 27 of 2020 are presented in the table below. Influenza A and B are cocirculating in the region, at a very low level compared to previous year (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 27 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 29 2019 to week 28 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (28) 70557 944 Cambodia (26) 567 68 China (28) 306338 30960 Fiji (8) 79 9 Japan (27) - 2489 Lao People's Democratic Republic (25) 1243 208 Malaysia (17) 1143 283 Mongolia (27) 4683 981 New Caledonia (6) 75 15 New Zealand - - Papua New Guinea - - Philippines (4) 92 8 Republic of Korea (6) 1409 505 Singapore (27) 2023 376 Viet Nam (22) 617 23 Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity continue to decrease, lower than in previous seasons. Outpatient ILI Surveillance China (North) During week 27 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 2.0%, lower than the last week (2.2%), and lower than the same week in 2017-2019 (2.5%, 2.2% and 2.4%). (Figure 2). Mongolia During week 25 2020, ILI activity in Mongolia has a decrease trend and similar to the lower tolerance limit (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2017-2021 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Influenza Situation Update | 3 Republic of Korea In week 27 of 2020, the overall weekly ILI rate was 1.8 ILI cases per 1,000 outpatient visits, higher than the previous week with 1.7 ILI cases per 1,000 outpatient visits and below the national epidemic threshold (5.9 ILI cases per 1,000 outpatient visits) (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 outpatient consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 27 of 2020, influenza sentinel hospital activity in Japan plateaued. The peak this year is lower than the previous years, but the general trend was similar to that seen in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to decrease in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 27 of 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 0.6 ILI cases per 1,000 consultations, which was the same as 0.6 ILI cases per 1,000 consultations recorded in the previous week (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 18.2 ILI cases per 1,000 consultations, which was higher than 17.8 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 27, 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 2.8%, lower than last week (3.3%), and lower than the same week of 2017-2019 (4.1%, 3.3% and 3.9%). ILI activity this season remains lower than previous seasons. (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 27 of 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 859 over 5.5 working days, which is significantly lower than the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2017-2021 (Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR The number of ILI cases presenting to sentinel sites has increased since week 19. In week 27 of 2020, it is similar to same week of previous years (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI From January to 28 June 2020, there have been 20,739 notifications of laboratory-confirmed influenza to the National Notifiable Diseases Surveillance System. Number of cases was lower than the five year average but showing a weekly trend similar to that seen in past years, except 2019 (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness General Practice-based ILI surveillance methods have changed in 2020 due to the COVID-19 response, limiting interpretability for influenza ILI surveillance. Collection of specimens commenced on 2nd June 2020. As of 10 July 2020, there have been 60 specimens collected from patients presenting to general practices with ILI symptoms, 0 (0%) of which were influenza positive. For the same period last year, 1056 specimens were tested of which 664 (62.9%) were influenza positive. (Source) Pacific Island Countries and Areas (PICs) - ILI Surveillance (no update) In the Pacific Island Countries and Areas, in week 22 of 2020, the number of ILI increased in Cook Islands, Samoa and Palau. (Figure 12). Figure 12: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Influenza Situation Update | 7 Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 29 July 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 and week 30 of 2020 are presented in the table below. Influenza A and B are cocirculating in the region, at a very low level compared to previous year (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 30 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 31 2019 to week 30 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (30) 80716 946 Cambodia (28) 611 69 China (29) 317122 30960 Fiji (8) 79 9 Japan (27) - 2489 Lao People's Democratic Republic (29) 533 0 Malaysia (17) 1143 283 Mongolia (29) 4711 981 New Caledonia (6) 75 15 New Zealand - - Papua New Guinea - - Philippines (4) 92 8 Republic of Korea (6) 1409 505 Singapore (30) 2134 376 Viet Nam (28) 704 23 Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity continue to decrease, lower than in previous seasons. Outpatient ILI Surveillance China (North) During week 29 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 1.8%, lower than the last week (1.9%), and lower than the same week in 2017-2019 (2.5%, 2.2%, and 2.2%). (Figure 2). Mongolia During week 30 2020, ILI activity in Mongolia has a decreasing trend and is similar to the lower tolerance limit (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2017-2021 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Influenza Situation Update | 3 Republic of Korea In week 29 of 2020, the overall weekly ILI rate was 1.8 ILI cases per 1,000 outpatient visits, lower than the previous week with 1.9 ILI cases per 1,000 outpatient visits and below the national epidemic threshold (5.9 ILI cases per 1,000 outpatient visits) (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 outpatient consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 28 of 2020, influenza sentinel hospital activity in Japan plateaued. The peak this year is lower than the previous years, but the general trend was similar to that seen in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to decrease in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 29 of 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 1.0 ILI cases per 1,000 consultations, which was higher than 0.6 ILI cases per 1,000 consultations recorded in the previous week (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 19.6 ILI cases per 1,000 consultations, which was lower than 20.0 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 29, 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 2.7%, higher than last week (2.6%), and lower than the same week of 2017-2019 (4.1%, 3.1% and 3.6%). ILI activity this season remains lower than previous seasons. (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 29 of 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 871 over 5.5 working days, which is significantly lower than the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2017-2021 Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: China National Influenza Center) (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR There is an increasing trend in the number of ILI cases presenting to sentinel sites since week 19 of 2020. The number of ILI cases in week 29 is similar to the same week in previous years but is lower than the number in week 28 (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI From January to 12 July 2020, there have been 20,830 notifications of laboratory-confirmed influenza to the National Notifiable Diseases Surveillance System. Number of cases was lower than the five year average but showing a weekly trend similar to that seen in past years, except 2019 (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness General Practice-based ILI surveillance methods have changed in 2020 due to the COVID-19 response, limiting interpretability for influenza ILI surveillance. Collection of specimens commenced on 2nd June 2020. As of 24 July 2020, there have been 111 specimens collected from patients presenting to general practices with ILI symptoms, 0 (0%) of which were influenza positive. For the same period last year, 1244 specimens were tested of which 763 (61.3%) were influenza positive. (Source) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 27 of 2020, the number of ILI cases increased in New Caledonia. (Figure 12). Figure 12: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Influenza Situation Update | 7 Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2020 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2020-2021 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 12 August 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 and week 32 of 2020 are presented in the table below. Influenza A and B are cocirculating in the region, at a very low level compared to previous year (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 32 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 33 2019 to week 32 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (32) 87272 946 Cambodia (28) 611 69 China (31) 334176 30973 Fiji (29) 292 30 Japan (31) - 2570 Lao People's Democratic Republic (29) 533 0 Malaysia (17) 1143 283 Mongolia (29) 4711 981 New Caledonia (6) 75 15 New Zealand - - Papua New Guinea - - Philippines (4) 92 8 Republic of Korea (6) 1409 505 Singapore (30) 2134 376 Viet Nam (28) 798 23 Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity continue to decrease, lower than in previous seasons. Outpatient ILI Surveillance China (North) During week 31 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 2.0%, same as the last week (2.0%), and lower than the same week in 2017-2019 (2.5%, 2.1%, and 2.2%). (Figure 2). Mongolia During week 31 2020, ILI activity in Mongolia has remained low, between the lower and upper tolerance limits (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2017-2021 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Republic of Korea In week 31 of 2020, the overall weekly ILI rate was 1.8 ILI cases per 1,000 outpatient visits, lower than the previous week with 2.3 ILI cases per 1,000 outpatient visits and below the national epidemic threshold (5.9 ILI cases per 1,000 outpatient visits) (Figure 4). Influenza Situation Update | 3 Figure 4: Weekly ILI incidence rate per 1,000 outpatient consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 30 of 2020, the number of cases reported weekly by sentinel hospital sites remained low in Japan. The peak this year is lower than the previous years, but the general trend was similar to that seen in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to decrease in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 31 of 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 0.8 ILI cases per 1,000 consultations, which was lower than 1.0 ILI cases per 1,000 consultations recorded in the previous week (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 16.4 ILI cases per 1,000 consultations, which was lower than 21.3 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 31, 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 2.7%, same as the previous week (2.7%), and lower than the same week of 2017-2019 (3.5%, 3.0% and 3.3%). ILI activity this season remains lower than previous seasons. (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 31 of 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 762 over 4.5 working days, which is significantly lower than the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2017-2021 (Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR In week 31 of 2020, the number of ILI cases presenting to sentinel sites was higher compared to previous week, but lower if compare to same week of previous year. (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI From 1 January to 26 July 2020, there have been 20,934 notifications of laboratory-confirmed influenza to the National Notifiable Diseases Surveillance System. Number of cases was lower than the five year average and have not showed an upward seasonal trend as seen in past years, except 2019 (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness General Practice-based ILI surveillance methods have changed in 2020 due to the COVID-19 response, limiting interpretability for influenza ILI surveillance. Collection of specimens commenced on 2nd June 2020. As of 31 July 2020, there have been 129 specimens collected from patients presenting to general practices with ILI symptoms, 0 (0%) of which were influenza positive. For the same period last year, 1,316 specimens were tested of which 809 (61.5%) were influenza positive. (Source) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 31 of 2020, the number of ILI cases increased in Samoa. (Figure 12). Figure 12: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Influenza Situation Update | 7 Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2020 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2020-2021 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 26 August 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 and week 34 of 2020 are presented in the table below. Influenza A and B are cocirculating in the region, at a very low level compared to previous year (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 34 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 35 2019 to week 34 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (34) 89316 946 Cambodia (28) 611 69 China (32) 344481 30975 Fiji (29) 292 30 Japan (32) - 2571 Lao People's Democratic Republic (33) 696 1 Malaysia (17) 1143 283 Mongolia (33) 4802 981 New Caledonia (6) 75 15 New Zealand (33) 159 - Papua New Guinea - - Philippines (4) 92 8 Republic of Korea (6) 1409 505 Singapore (33) 2231 376 Viet Nam (28) 798 23 Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity continue to decrease, lower than in previous seasons. Outpatient ILI Surveillance China (North) During week 33 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 1.9%, lower than last week (2.0%), and lower than the same week in 2017-2019 (2.3%, 2.1%, and 2.1%) (Figure 2). Mongolia During week 33 2020, ILI activity in Mongolia has remained low, between the lower and upper tolerance limits (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2017-2021 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Influenza Situation Update | 3 Republic of Korea In week 33 of 2020, the overall weekly ILI rate was 1.8 ILI cases per 1,000 outpatient visits, lower than the previous week with 2.1 ILI cases per 1,000 outpatient visits and below the national epidemic threshold (5.9 ILI cases per 1,000 outpatient visits) (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 outpatient consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 32 of 2020, the number of cases reported weekly by sentinel hospital sites remained low in Japan. The peak this year is lower than the previous years, but the general trend was similar to that seen in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to decrease in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 33 of 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 0.7 ILI cases per 1,000 consultations, which was higher than 0.6 ILI cases per 1,000 consultations recorded in the previous week (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 15.3 ILI cases per 1,000 consultations, which was lower than 16.1 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 33, 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 2.7%, same as the previous week (2.7%), and lower than the same week of 2017-2019 (3.5%, 2.8%, and 3.0%). ILI activity this season remains lower than previous seasons (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 33 of 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 710 over 4.5 working days, which is significantly lower than the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2017-2021 Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: China National Influenza Center) (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR In week 33 of 2020, the number of ILI cases presenting to sentinel sites was the same level as the previous week, but lower than the same week of the previous year (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI From 1 January to 9 August 2020, there have been 21,005 notifications of laboratory-confirmed influenza to the National Notifiable Diseases Surveillance System. The number of cases was lower than the five year average and has not shown an upward seasonal trend as seen in past years, except 2019 (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness General Practice-based ILI surveillance methods have changed in 2020 due to the COVID-19 response, limiting interpretability for influenza ILI surveillance. Collection of specimens commenced on 2nd June 2020. As of 14 August 2020, there have been 169 specimens collected from patients presenting to general practices with ILI symptoms, 0 (0%) of which were influenza positive. For the same period last year, 1,437 specimens were tested of which 857 (59.6%) were influenza positive. (Source) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 33 of 2020, the number of ILI cases increased in Samoa with 1,267 ILI cases reported in week 33. The etiology of these ILI cases is yet to be confirmed (Figure 12). Figure 12: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Influenza Situation Update | 7 Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2020 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2020-2021 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 9 September 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 and week 36 of 2020 are presented in the table below. Influenza A and B are cocirculating in the region, at a very low level compared to previous year (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 36 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 37 2019 to week 36 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (36) 96294 946 Cambodia (28) 611 69 China (35) 365001 30980 Fiji (29) 292 30 Japan (33) - 2591 Lao People's Democratic Republic (35) 752 1 Malaysia (17) 1143 283 Mongolia (34) 4811 981 New Caledonia (6) 75 15 New Zealand (33) 159 - Papua New Guinea - - Philippines (4) 92 8 Republic of Korea (6) 1409 505 Singapore (35) 2313 376 Viet Nam (28) 798 23 Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity continue to decrease, lower than in previous seasons. Outpatient ILI Surveillance China (North) During week 35 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 1.8%, higher than last week (1.7%), and lower than the same week in 2017-2019 (2.4%, 2.0%, and 2.0%). (Figure 2). Mongolia During week 35 2020, ILI activity in Mongolia has remained low, between the lower and upper tolerance limits (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2017-2021 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Influenza Situation Update | 3 Republic of Korea In week 35 of 2020, the overall weekly ILI rate was 2.0 ILI cases per 1,000 outpatient visits, lower than the previous week with 2.1 ILI cases per 1,000 outpatient visits and below the national epidemic threshold (5.9 ILI cases per 1,000 outpatient visits) (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 outpatient consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 34 of 2020, the number of cases reported weekly by sentinel hospital sites remained low in Japan. The peak this year is lower than the previous years, but the general trend was similar to that seen in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to decrease in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 35 of 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 0.6 ILI cases per 1,000 consultations, which was higher than 0.4 ILI cases per 1,000 consultations recorded in the previous week (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 22.7 ILI cases per 1,000 consultations, which was higher than 17.0 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 35, 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 2.7%, higher than the previous week (2.6%), lower than the same week of 2017 and 2019 (3.3% and 2.8%), but higher than the same week of 2018 (2.6%). ILI activity this season remains lower than previous seasons. (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 35 of 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 730 over 5.5 working days, which is significantly lower than the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2017-2021 (Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR In week 35 of 2020, the number of ILI cases presenting to sentinel sites was higher compared to previous week, but lower to the same week of the previous year. (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI From 1 January to 23 August 2020, there have been 21,079 notifications of laboratory-confirmed influenza to the National Notifiable Diseases Surveillance System. Number of cases was lower than the five-year average and have not showed an upward seasonal trend as seen in past years (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness General Practice-based ILI surveillance methods have changed in 2020 due to the COVID-19 response, limiting interpretability for influenza ILI surveillance. Collection of specimens commenced on 2nd June 2020. As of 28 August 2020, there have been 194 specimens collected from patients presenting to general practices with ILI symptoms, 0 (0%) of which were influenza positive. For the same period last year, 1,517 specimens were tested of which 886 (59.6%) were influenza positive. (Source) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 35 of 2020, increase in Republic of Marshall Islands and Commonwealth of the Northern Mariana Islands. A total of 1,110 ILI cases were reported in Samoa in week 34, which is lower than previous week (1,267 cases) (Figure 12). Figure 12: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Influenza Situation Update | 7 Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2020 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2020-2021 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 23 September 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 and week 38 of 2020 are presented in the table below. Influenza A and B are cocirculating in the region, at a very low level compared to previous year (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 38 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 39 2019 to week 38 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (38) 98392 946 Cambodia (35) 755 94 China (37) 384828 30986 Fiji (29) 292 30 Japan (36) - 2607 Lao People's Democratic Republic (37) 864 2 Malaysia (17) 1143 283 Mongolia (37) 4849 981 New Caledonia (6) 75 15 New Zealand (37) 198 - Papua New Guinea - - Philippines (4) 92 8 Republic of Korea (6) 1409 505 Singapore (35) 2313 376 Viet Nam (37) 917 23 Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity continue to decrease, lower than in previous seasons. Outpatient ILI Surveillance China (North) During week 37 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 2.0%, higher than last week (1.9%), and lower than the same week in 2017-2019 (2.5%, 2.1% and 2.3). (Figure 2). Mongolia During week 37 2020, ILI activity in Mongolia has remained low, between the lower and upper tolerance limits (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2017-2021 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Influenza Situation Update | 3 Republic of Korea In week 37 of 2020, the overall weekly ILI rate was 1.4 ILI cases per 1,000 outpatient visits, lower than the previous week with 1.7 ILI cases per 1,000 outpatient visits and below the national epidemic threshold (5.9 ILI cases per 1,000 outpatient visits) (Figure 4). Figure 4: Weekly ILI incidence rate per 1,000 outpatient consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 36 of 2020, the number of cases reported weekly by sentinel hospital sites remained low in Japan. The peak this year is lower than the previous years, but the general trend was similar to that seen in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to decrease in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 37 of 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 0.3 ILI cases per 1,000 consultations, which was lower than 0.7 ILI cases per 1,000 consultations recorded in the previous week (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 14.5 ILI cases per 1,000 consultations, which was lower than 17.2 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 37, 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 3.7%, higher than the previous week (3.1%), higher than the same week of 2017 to 2019 (3.3%, 2.8% and 3.3%). ILI activity this season is higher than previous seasons. (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 37 of 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 818 over 5.5 working days, which is significantly lower than the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2017-2021 Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: China National Influenza Center) (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR In week 37 of 2020, the number of ILI cases presenting to sentinel sites was higher compared to previous week, but lower than the same week of the previous year. (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI From 1 January to 6 September 2020, there have been 21,119 notifications of laboratory-confirmed influenza to the National Notifiable Diseases Surveillance System. Number of cases was lower than the five-year average and have not showed an upward seasonal trend as seen in past years (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness General Practice-based ILI surveillance methods have changed in 2020 due to the COVID-19 response, limiting interpretability for influenza ILI surveillance. Collection of specimens commenced on 2nd June 2020. As of 11 September 2020, there have been 212 specimens collected from patients presenting to general practices with ILI symptoms, 0 (0%) of which were influenza positive. For the same period last year, 1577 specimens were tested of which 905 (57.4%) were influenza positive. (Source) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 37 of 2020, there was an increase in ILI cases in New Caledonia, French Polynesia, Wallis and Futuna, Cook Islands, Republic of Marshall Islands and Tonga. Samoa reported an increase in ILI cases with 958 cases reported in Week 37, which is higher than the previous week (925 cases) (Figure 12). Figure 12: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Influenza Situation Update | 7 Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2020 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2020-2021 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish
Bi-weekly Influenza Situation Update 7 October 2020 Virological Surveillance Summary The total number of specimens and number of positive specimens reported to FluNet by Western Pacific Region countries and areas between week 1 and week 40 of 2020 are presented in the table below. Influenza A and B are cocirculating in the region, at a very low level compared to previous year (Figure 1). It should be noted that several countries and areas have not reported in 2020. Table 1: Cumulative data reported to FluNet from Western Pacific Region, week 1 2020 to week 40 2020 Figure 1: Number of specimens positive for influenza by subtype, Western Pacific Region, week 41 2019 to week 40 2020 (Source: WHO FLUNET) Country (most recent week of report) Total number of specimens processed Total number of influenza positive specimens Australia (40) 101,072 946 Cambodia (35) 755 94 China (39) 400,592 30,989 Fiji (29) 292 30 Japan (38) - 2,607 Lao People's Democratic Republic (37) 864 2 Malaysia (17) 1,143 283 Mongolia (38) 4,872 981 New Caledonia (6) 75 15 New Zealand (37) 198 - Papua New Guinea - - Philippines (4) 92 8 Republic of Korea (6) 1,409 505 Singapore (35) 2,313 376 Viet Nam (37) 917 23 Influenza Situation Update | 2 Influenza surveillance summary Influenza surveillance in the WHO Western Pacific Region is based on outpatient and inpatient sentinel indicator based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups included and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted and information is available. The WHO surveillance case definition for influenza-like illness (ILI) is an acute respiratory infection with a measured fever of ≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratory infection (ARI) with a history of fever or measured fever of ≥38oC and cough, with symptom onset within 10 days that requires hospitalization. Sentinel site data should be interpreted with caution since the number of sites reporting may vary between weeks. Countries in the temperate zone of the Northern Hemisphere In countries within the temperate zone of the Northern Hemisphere, ILI and influenza activity continue to decrease, lower than in previous seasons. Outpatient ILI Surveillance China (North) During week 38 2020, the percentage of visits for ILI at national sentinel hospitals in Northern China was 2.1%, the same as last week (2.1%), lower than the same week in 2017 and 2019 (2.5%, 2.1%), and equal to the same week of 2018 (2.1%). (Figure 2). Mongolia During week 39 2020, ILI activity in Mongolia has remained low, between the lower and upper tolerance limits (Figure 3). Figure 2: Percentage of visits for ILI at sentinel hospitals in Northern China, 2017-2021 (Source: China National Influenza Center) Figure 3: Proportion of outpatient ILI visits per 10,000 people in Mongolia, 2018-2020 (Source: Mongolia National Influenza Center) Republic of Korea In week 39 of 2020, the overall weekly ILI rate was 1.3 ILI cases per 1,000 outpatient visits, lower than the previous week with 1.5 ILI cases per 1,000 outpatient visits and below the national epidemic threshold (5.8 ILI cases per 1,000 outpatient visits) (Figure 4). Influenza Situation Update | 3 Figure 4: Weekly ILI incidence rate per 1,000 outpatient consultations, Republic of Korea, 2015-2020 (Source: Korean Centres for Disease Control and Prevention) Sentinel influenza surveillance Japan In week 38 of 2020, the number of cases reported weekly by sentinel hospital sites remained low in Japan. The peak this year is lower than the previous years, but the general trend was similar to that seen in previous seasons (Figure 5). Figure 5: Number of influenza cases reported weekly per reporting sentinel hospital site, Japan 2010-2020 (Source: Japan National Institute of Infectious Diseases) Influenza Situation Update | 4 Countries/areas in the tropical zone ILI and influenza activity continued to decrease in most of the countries and areas. Surveillance Hong Kong SAR (China) – ILI and hospital Surveillance In week 39 of 2020, the average consultation rate for ILI among sentinel general outpatient clinics was 0.7 ILI cases per 1,000 consultations, which was higher than 0.5 ILI cases per 1,000 consultations recorded in the previous week (Figure 6). The average consultation rate for ILI among sentinel private medical practitioners was 14.7 ILI cases per 1,000 consultations, which was lower than 17.0 recorded in the previous week (Figure 7). Figure 6: ILI consultation rates at sentinel general outpatient clinics, Hong Kong SAR 2019-2020 (Source: Hong Kong Centre for Health Protection) Figure 7: ILI consultation rates at sentinel private doctors, Hong Kong SAR 2016-2020 (Source: Hong Kong Centre for Health Protection) China (South) - ILI Surveillance During week 38, 2020, the percentage of visits for ILI at national sentinel hospitals in Southern China was 3.9%, higher than the previous week (3.5%), higher than the same week of 2017 to 2019 (3.1%, 2.9% and 3.2%). ILI activity this season is higher than previous seasons. (Figure 8). Singapore – Acute Respiratory Infection (ARI) Surveillance In week 38 of 2020, the average daily number of patients seeking treatment in polyclinics for ARI was 1123 over 5.5 working days, which is significantly lower than the same time period in 2019 (Figure 9). Figure 8: Percentage of visits due to ILI at national sentinel hospitals in Southern China, 2017-2021 (Source: China National Influenza Center) Figure 9: Average daily polyclinic attendances for ARI in Singapore, 2019-2020 (Source: Singapore Ministry of Health) Influenza Situation Update | 5 Lao PDR In week 38 of 2020, the number of ILI cases presenting to sentinel sites was higher compared to the previous week, but lower than the same week of the previous year. (Figure 10). Figure 10: Weekly number of ILI presentations at sentinel sites, 2016-2020, Lao PDR (Source: Lao National Center for Laboratory and Epidemiology) Countries in the temperate zone of the southern hemisphere In the temperate zone of the southern hemisphere, influenza activity is reported during the influenza season usually starting in May in Australia and New Zealand. Australia – Laboratory-confirmed influenza and ILI From 1 January to 20 September 2020, there have been 21,156 notifications of laboratory-confirmed influenza to the National Notifiable Diseases Surveillance System. The number of cases was lower than the five-year average and has not shown an upward seasonal trend as seen in past years (Figure 11). Figure 11: Australian notifications of laboratory confirmed influenza (Source: National Notifiable Diseases Surveillance System, Australian Department of Health) Influenza Situation Update | 6 New Zealand – Influenza like Illness General Practice-based ILI surveillance methods have changed in 2020 due to the COVID-19 response, limiting interpretability for influenza ILI surveillance. Collection of specimens commenced on 2nd June 2020. As of 25 September 2020, there have been 222 specimens collected from patients presenting to general practices with ILI symptoms, 0 (0%) of which were influenza positive. For the same period last year, 1612 specimens were tested of which 916 (56.8%) were influenza positive. (Source) Pacific Island Countries and Areas (PICs) - ILI Surveillance In the Pacific Island Countries and Areas, in week 39 of 2020, there was an increase in ILI cases in New Caledonia, Wallis and Futuna, and Samoa. There was an increase in ILI cases in Samoa with 1125 cases reported in Week 39, which is higher than the 958 cases reported in the previous week (Figure 12). Figure 12: Reported cases of influenza-like illness in Pacific Island Countries (Source: PacNet bulletin) Influenza Situation Update | 7 Global influenza situation updates Virological update Global update Others: • Recommended composition of influenza virus vaccines for use in the 2020 southern hemisphere influenza season Link • Recommended composition of influenza virus vaccines for use in the 2020-2021 northern hemisphere influenza season Link • Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines Link • 4th WHO Informal Consultation on Improving Influenza Vaccine Virus Selection Link WHO's YouTube Channel: film exploring a number of key aspects of the constant evolution of influenza viruses and associated impacts on public health. Arabic, Chinese, English, French, Russian, Spanish