Epidemiological update: Outbreaks of Zika virus and complications potentially linked to the Zika virus infection, 28 July 2016
Since 1 February 2016, Zika virus infection and the related clusters of microcephaly cases and other neurological disorders constitute a public health emergency of international concern (PHEIC). Since 2015, and as of 28 July 2016, WHO has reported 64 countries and territories with mosquito-borne transmission. There is now a scientific consensus that Zika virus is a cause of microcephaly and Guillain-Barré syndrome.
Page last updated: 29 July 2016Since 1 February 2016, Zika virus infection and the related clusters of microcephaly cases and other neurological disorders constitute a public health emergency of international concern (PHEIC). Since 2015, and as of 28 July 2016, WHO has reported 64 countries and territories with mosquito-borne transmission. There is now a scientific consensus that Zika virus is a cause of microcephaly and Guillain-Barré syndrome.
As of 27 July 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.
New developments since the last epidemiological update
One country and one territory have reported mosquito-borne Zika virus transmission for the first time, in the week to 27 July 2016: Antigua and Barbuda and Turks and Caicos (United Kingdom).In the United States of America, one case of Zika virus infection, whose mode of transmission is being investigated in Utah, and non-travel-related Zika infections are being investigated in Florida.On 25 July, the Department of Health in Spain reported the birth of a child presenting with microcephaly in Catalonia. The woman was known to be infected by Zika and dengue viruses and the case was initially reported on 5 May when malformations were detected in the foetus.Colombia declared the end of the Zika epidemic on 26 July 2016.US CDC published interim guidance for health care providers caring for pregnant women with possible Zika virus exposure and updated their interim guidance for prevention of sexual transmission of 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 1 062 travel-associated Zika virus infections through The European Surveillance System (TESSy).
EU’s Outermost Regions and Territories
As of 28 July 2016: Guadeloupe: 25 450 suspected cases have been detected, an increase of 1 505 suspected cases since last week. The weekly number of cases has been slightly declining during the past two weeks.French Guiana: 9 225 suspected cases have been detected, an increase of 140 since last week. The weekly number of cases has been decreasing over the past three weeks. Martinique: 33 900 suspected cases have been reported, an increase of 455 since last week. The weekly number of cases is declining. St Barthélemy: 330 suspected cases have been detected, an increase of 60 suspected cases since last week. The virus is still actively circulating.St Martin: 1 730 suspected cases have been detected, an increase of 135 suspected cases since last week. The weekly number of cases remains stable compared to the previous week.
Update on microcephaly and/or central nervous system (CNS) malformations potentially associated with Zika virus infection
As of 28 July 2016, microcephaly and other central nervous system (CNS) malformations associated with Zika virus infection or suggestive of congenital infection have been reported by 14 countries or territories. Brazil has reported the highest number of cases. Between October 2015 and 20 July 2016, Brazil reported 8 703 suspected cases of microcephaly and other nervous system disorders suggestive of congenital infection. Of these, 1 749 are confirmed cases of microcephaly, 277 of which are laboratory-confirmed for Zika virus infection, according to the Ministry of Health. Fifteen countries and territories worldwide 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) 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. Nature publication: 'Brazil ask whether Zika acts alone to cause birth defects'.
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.
Table 1. Countries and territories with reported confirmed autochthonous cases of Zika virus infection in the past three months, as of 29 July 2016
|Country||Last case since 3 months|
|American Samoa||Widespread transmission|
|Cape Verde||Widespread 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 Maarten||Widespread transmission|
|Trinidad and Tobago||Widespread transmission|
|US Virgin Islands||Widespread transmission|
|Antigua and Barbuda||Sporadic transmission|
|Sint Eustatius||Sporadic transmission|
|Turks and Caicos Islands||Sporadic transmission|
Figure 1. Countries or territories with reported confirmed autochthonous cases of Zika virus infection in the past three months, as of 29 July 2016