Epidemiological update: Outbreaks of Zika virus and complications potentially linked to the Zika virus infection, 11 August 2016
Since 1 February 2016, Zika virus infection and the related clusters of microcephaly cases and other neurological disorders have been declared to constitute a public health emergency of international concern (PHEIC). Since 2015, and as of 10 August 2016, WHO has reported 66 countries and territories with mosquito-borne transmission, including most recently the State of Florida in the USA. As of 10 August 2016, 15 countries or territories have reported microcephaly and other central nervous system (CNS) malformations potentially associated with Zika virus infection or suggestive of congenital infection.
Between 4 August and 11 August 2016, the Florida Department of Health has reported ten additional non-travel related cases in Miami-Dade County. The Department of Health still believes that active transmission is only taking place in this previously identified one-square-mile area in Miami-Dade County. As of 11 August, the Florida Department of Health has reported 404 travel-related and 25 non-travel-related Zika infections and 57 infections in pregnant women. Media are reporting that three cases are being investigated that do not have a clear link with the one-square-mile area in Miami-Dade County, including one recent case in Palm Beach county.
New developments since the last epidemiological update
A field trial for genetically-modified mosquitoes engineered to reduce Aedes aegypti populations in Florida has been approved by the Food and Drug Administration (FDA). However, mosquitoes still need to meet state and local requirements before they can be used. If approved, the mosquitoes will be released in Key Haven, Florida.
On 9 August, a Zika-related infant death of an infant born with birth defects including microcephaly in Texas received media attention as it was the first Zika-associated-death in Texas.
On 10 August, the Cayman Islands reported the first two cases of locally-acquired Zika virus.
EU/EEA imported cases
Since week 45/2015, 18 countries (Austria, Belgium, the Czech Republic, Denmark, Finland, France, Ireland, Italy, Luxembourg, Malta, the Netherlands, Norway, Portugal, Romania, Slovenia, Spain, Sweden and the UK) have reported 1 230 travel-associated Zika virus infections through The European Surveillance System (TESSy).
EU’s Outermost Regions and Territories
As of 11 August 2016:
Guadeloupe: 27 330 suspected cases have been detected, an increase of 815 suspected cases since last week. The weekly number of cases has decreased compared to the previous two weeks.
French Guiana: 9 400 suspected cases have been detected, an increase of 65 cases since last week. The weekly number of cases has been decreasing over the last two weeks.
Martinique: 34 740 suspected cases have been reported, an increase of 250 since last week. The weekly number of cases is declining.
St Barthélemy: 440 suspected cases have been detected, an increase of 65 suspected cases since last week. The virus is still actively circulating.
St Martin: 1 895 suspected cases have been detected, an increase of 75 suspected cases since last week. The weekly number of cases has decreased compared to the previous week.
Update on microcephaly and/or central nervous system (CNS) malformations potentially associated with Zika virus infection
As of 10 August 2016, microcephaly and other central nervous system (CNS) malformations associated with Zika virus infection or suggestive of congenital infection had been reported by 15 countries or territories. Brazil has reported the highest number of cases. Sixteen 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.
Since February 2016, 11 countries have reported evidence of person-to-person transmission of Zika virus, probably via a sexual route.
In the EU, Spain (2) and Slovenia (1) have reported congenital malformations associated with Zika virus infection after travel in the affected areas. Cases have also been detected in the EU’s Outermost Regions and Territories in Martinique, French Guiana and French Polynesia.
The spread of the Zika virus epidemic in the Americas is likely to continue as the vectors (Aedes aegypti and Aedes albopictus mosquitoes) are widely distributed there. The likelihood of travel-related cases in the EU is increasing. A detailed risk assessment is available here. As neither treatment nor vaccines are available, prevention is based on personal protection measures. Pregnant women should consider postponing non-essential travel to Zika-affected areas.
Zika virus infection atlas is also available on the ECDC website. ECDC published an updated a Rapid Risk Assessment on 12 July 2016.
ECDC publishes information concerning vector distribution on the ECDC website, showing the distribution of the vector species at ‘regional’ administrative level (NUTS3).
Table 1. Countries and territories with reported confirmed autochthonous cases of Zika virus infection in the past three months, as of 12 August 2016
|Countries||Areas (non-tropical countries only)||Last case since 3 months|
|American Samoa||Widespread transmission|
|Antigua and Barbuda||Sporadic transmission|
|Cape Verde||Widespread transmission|
|Cayman Islands||Sporadic transmission|
|Costa Rica||Widespread transmission|
|Dominican Republic||Widespread transmission|
|El Salvador||Widespread transmission|
|French Guiana||Widespread transmission|
|Micronesia, Federated States of||Widespread transmission|
|Puerto Rico||Widespread transmission|
|Saint Lucia||Widespread transmission|
|Saint Martin||Widespread transmission|
|Saint Vincent and the Grenadines||Widespread transmission|
|Sint Eustatius||Sporadic transmission|
|Sint Maarten||Widespread transmission|
|Trinidad and Tobago||Widespread transmission|
|Turks and Caicos Islands||Sporadic transmission|
|United States of America||Florida (Miami-Dade and Broward counties)||Widespread transmission|
|US Virgin Islands||Sporadic transmission|
The classification of countries above is based on: 1) number of reported autochthonous confirmed cases; 2) number of countries who report a zika virus transmission or a country’s transmission status changes; 3) duration of the circulation.
Figure 1. Countries or territories with reported confirmed autochthonous cases of Zika virus infection in the past three months, as of 12 August 2016
ECDC Zika epidemic rapid risk assessment includes updated risk classification approach
4 Apr 2017 - The latest update of ECDC’s rapid risk assessment on the Zika epidemic includes an assessment of the level of risk for travellers based on an adaptation of the WHO interim guidance on the Zika virus country classification scheme and the recent epidemiological and scientific information.
Recent scientific findings based on literature reviewed after the ninth update of the ECDC Rapid Risk Assessment on Zika virus infection (19 October to 27 January 2017)
6 Feb 2017 - This scientific advance presents relevant scientific literature and outlines the main findings from Zika virus research published between 19 October 2016