ZIKA VIRUS
SITUATION REPORT ZIKA VIRUS MICROCEPHALY GUILLAIN-BARRÉ SYNDROME 4 AUGUST 2016 As of 3 August 2016, 68 countries and territories (Fig. 1, Table 1) have reported evidence of mosquito-borne Zika virus transmission since 2007 (65 of these countries and territories have reported evidence of mosquito-borne Zika virus transmission since 2015): 51 countries and territories with a first reported outbreak from 2015 onwards (Table 1). Four countries are classified as having possible endemic transmission or have reported evidence of local mosquito-borne Zika infections in 2016. 13 countries and territories have reported evidence of local mosquito-borne Zika infections in or before 2015, but without documentation of cases in 2016, or with the outbreak terminated. The United States of America reported mosquito-borne Zika virus transmission for the first time on 29 July 2016. Since February 2016, 11 countries have reported evidence of person-to-person transmission of Zika virus, probably via a sexual route (Table 2). As of 3 August 2016, 14 countries or territories have reported microcephaly and other central nervous system (CNS) malformations potentially associated with Zika virus infection or suggestive of congenital infection. No additional countries or territories have reported microcephaly in the last week. Three of the 14 total countries reported microcephaly cases born from mothers in countries with no endemic Zika virus transmission but who reported recent travel history to Zika-affected countries in the WHO Region of the Americas (Table 3). As of 3 August 2016, the United States Centers for Disease Control and Prevention (USCDC) reported 13 live-born infants with birth defects and six pregnancy losses with birth defects with laboratory evidence of Zika virus infection.1 As of 3 August 2016, 15 countries and territories worldwide have reported an increased incidence of Guillain-Barré syndrome (GBS) and/or laboratory confirmation of a Zika virus infection among GBS cases (Table 4). In Guinea-Bissau, on 29 June 2016, Institute Pasteur Dakar (IPD) confirmed that three of 12 samples tested positive for Zika by PC-R. All 12 samples tested negative against IgM Zika. One additional sample from a recent case also tested positive for Zika virus infection. 1
https://www.cdc.gov/zika/geo/pregnancy-outcomes.html
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All four samples were sent to IPD on 1 July for gene sequencing and the results are pending. Twenty-two additional samples were collected and sent for testing; the results are still pending. A roster of WHO technical and communication officers is available to answer media queries during the Olympics.2 WHO has developed advice and information on diverse topics in the context of Zika virus.3,4 Risk assessment Overall, the global risk assessment has not changed. Zika virus continues to spread geographically to areas where competent vectors are present. Although a decline in cases of Zika infection has been reported in some countries, or in some parts of countries, vigilance needs to remain high. At this stage, based on the evidence available, there is no overall decline in the outbreak. Figure 1. Cumulative number of countries, territories and areas by WHO region5 reporting mosquito-borne Zika virus transmission in years (2007–2014), and monthly from 1 January 2015 to 3 August 2016
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http://who.int/mediacentre/contacts/dgo/en/ http://www.who.int/csr/resources/publications/zika/en/ 4 http://www.who.int/emergencies/zika-virus/en/ ; http://www.who.int/risk-communication/zika-virus/en/ 5 http://www.who.int/about/regions/en/
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Table 1. Countries and territories reporting mosquito-borne Zika virus transmission Classification WHO Regional Office Country / territory / area AFRO Total Cabo Verde; Guinea-Bissau 2 Anguilla; Antigua and Barbuda; Argentina; Aruba; Barbados; Belize; Bolivia (Plurinational State of), BONAIRE, SINT EUSTATIUS and SABA – Netherlands*; Brazil; Colombia; Costa Rica; Cuba; Curaçao; Dominica; Dominican Republic; Ecuador; El Salvador; French Guiana; Grenada; Guadeloupe; Guatemala; Guyana; Haiti; 43 Honduras; Jamaica; Martinique; Mexico; Nicaragua; Panama; Paraguay; Peru; Puerto Rico; Saint Barthélemy; Saint Lucia; Saint Martin; Saint Vincent and the Grenadines; Sint Maarten; Suriname; Trinidad and Tobago; Turks and Caicos; United States of America; United States Virgin Islands; Venezuela (Bolivarian Republic of) American Samoa; Fiji; Marshall Islands; Micronesia (Federated 6 States of); Samoa; Tonga 51 Indonesia; Thailand Philippines; Viet Nam 2 2 4 1 1 2 9 13 68
Category 1: Countries with a first reported outbreak from 2015 onwards
AMRO/PAHO
WPRO Subtotal Category 2: Countries SEARO with possible endemic transmission or evidence of local mosquito-borne WPRO Zika infections in 2016 Subtotal Category 3: Countries AFRO with evidence of local PAHO/AMRO mosquito-borne Zika infections in or before SEARO 2015, but without documentation of cases in WPRO 2016, or outbreak terminated Subtotal Total
Gabon ISLA DE PASCUA – Chile** Bangladesh; Maldives Cambodia; Cook Islands**; French Polynesia**; Lao People’s Democratic Republic; Malaysia; New Caledonia; Papua New Guinea; Solomon Islands; Vanuatu
*This includes confirmed Zika virus cases reported in BONAIRE – Netherlands, SINT EUSTATIUS and SABA – Netherlands. **These countries and territories have not reported Zika virus cases in 2015 or 2016. Categories are defined as follows (Fig. 2): Category 1: Countries with a first reported outbreak from 2015 onwards A laboratory confirmed, autochthonous, mosquito-borne case of Zika virus infection in an area where there is no evidence of circulation of the virus in the past (prior 2015), whether it is detected and reported by the country itself or by another state party diagnosing returning travellers OR A laboratory confirmed, autochthonous, mosquito-borne case of Zika virus infection in an area where transmission has been previously interrupted. The assumption is that the size of the susceptible population has built up to a sufficient level to allow transmission again; the size of the outbreak will be a function of the size of the susceptible population OR An increase of the incidence of laboratory confirmed, autochthonous, mosquito-borne Zika virus infection in areas where there is on-going transmission, above two standard deviations of the baseline rate, or doubling the number of cases over a 4-week period. Clusters of febrile illnesses, in particular when epidemiologically-linked to a confirmed case, should be microbiologically investigated. Category 2: Countries with possible endemic transmission or evidence of local mosquito-borne Zika infections in 2016 with the reporting period beginning in 2007 Countries or territories that have reported an outbreak with consistent presence of laboratory confirmed, autochthonous, mosquito-borne cases of Zika virus infection 12 months after the outbreak OR Countries or territories where Zika virus has been circulating for several years with consistent presence of laboratory confirmed, autochthonous, mosquito-borne cases of Zika virus infection or evidence of local mosquito-borne Zika infections in 2016. Reports can be from the country or territory where infection occurred, or from a third party where the case is first recorded according to the International Health Regulations (IHR 2005). Countries with evidence of infection prior to 2007 are listed in http://www.who.int/bulletin/online_first/16-171082.pdf Category 3: Countries with evidence of local mosquito-borne Zika infections in or before 2015, but without documentation of cases in 2016, or outbreak terminated with the reporting period beginning in 2007 Absence of confirmed cases over a 3-month period in a specific geographical area with climatic conditions suitable for year-round arbovirus transmission, or over a 12-month period in an area with seasonal vector activity.
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Figure 2. Country categorization according to dates of first and last report of confirmed Zika virus
Table 2. Countries reporting non mosquito-borne Zika virus transmission since February 2016 Classification WHO Regional Office Country / territory / area Argentina, Canada, Chile, Peru, United States of America France, Germany, Italy, Portugal, Spain New Zealand Total 5 5 1 11 Countries with evidence of AMRO/PAHO person-to-person transmission of Zika virus, other than mosquito- EURO borne transmission WPRO Total
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Figure 3. Global spread of Zika virus, 2013-2016
ISLA DE PASCUA – Chile is not displayed in the map given uncertainty about the date of onset of the outbreak there. Circulation of Zika virus in Thailand, Cambodia and Lao People’s Democratic Republic started before 2013. Countries where sexual transmission occurred are not represented in this map. Available information does not permit measurement of the risk of infection in any country; the variation in transmission intensity among countries is therefore NOT represented on this map. Zika virus is not necessarily present throughout the countries/territories shaded in this map.
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Table 3. Countries, territories and areas reporting microcephaly and/or CNS malformation cases potentially associated with Zika virus infection Reporting country or territory Brazil Cabo Verde Colombia El Salvador French Guiana French Polynesia Marshall Islands Martinique Panama Paraguay Puerto Rico Slovenia Spain United States of America*
Number of microcephaly and/or CNS malformation cases suggestive of congenital Zika infections or potentially associated with a Zika virus infection 1749 6
Probable location of infection Brazil Cabo Verde Colombia El Salvador French Guiana French Polynesia Marshall Islands Martinique Panama Paraguay Puerto Rico Brazil Colombia, Venezuela (Bolivarian Republic of) Undetermined**
9 7 21 2 8 2 8 1 9 8 5 10 2 1 11 1 2 19 12
* US-CDC has modified the way information is displayed. To protect the privacy of the women and children affected by Zika, US-CDC is not reporting individual state, tribal, territorial or jurisdictional level data. **The probable locations of three of the infections were Brazil (1 case), Haiti (1 case) and Mexico, Belize or Guatemala (1 case).
Table 4. Countries, territories or areas reporting Guillain-Barré syndrome (GBS) potentially associated with Zika virus infection Classification Reported increase in incidence of GBS cases, with at least one GBS case with confirmed Zika virus infection No increase in GBS incidence reported, but at least one GBS case with confirmed Zika virus infection
Country / territory / area Brazil, Colombia, Dominican Republic, El Salvador*, French Guiana, French Polynesia, Honduras, Jamaica, Martinique, Suriname, Venezuela (Bolivarian Republic of) Guadeloupe , Haiti, Panama, Puerto Rico 13
*GBS cases with previous history of Zika virus infection were reported by the International Health Regulations (2005) National Focal Point in United States of America.
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http://portalsaude.saude.gov.br/index.php/cidadao/principal/agencia-saude/24769-microcefalia-1-749-casos-confirmados-no-brasil http://www.ins.gov.co/boletinepidemiologico/Boletn%20Epidemiolgico/2016%20Bolet%C3%ADn%20epidemiol%C3%B3gico%20semana%2027.pdf 8 http://www.invs.sante.fr/Publications-et-outils/Points-epidemiologiques/Tous-les-numeros/Antilles-Guyane/2016/Situationepidemiologique-du-virus-Zika-aux-Antilles-Guyane.-Point-au-21-juillet-2016 9 http://www.invs.sante.fr/Publications-et-outils/Points-epidemiologiques/Tous-les-numeros/Antilles-Guyane/2016/Situationepidemiologique-du-virus-Zika-aux-Antilles-Guyane.-Point-au-21-juillet-2016 10 http://www.mspbs.gov.py/v3/paraguay-reporta-sus-dos-primeros-casos-de-microcefalia-asociados-al-zika/ 11 http://www.nejm.org/doi/pdf/10.1056/NEJMoa1600651 12 http://www.cdc.gov/zika/geo/pregnancy-outcomes.html 13 http://www.invs.sante.fr/Publications-et-outils/Points-epidemiologiques/Tous-les-numeros/Antilles-Guyane/2016/Situationepidemiologique-du-virus-Zika-aux-Antilles-Guyane.-Point-au-23-juin-2016
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