Epidemiological update: Outbreaks of Zika virus and complications potentially linked to the Zika virus infection, 2 June 2016

New developments since the last epidemiological update published on 20 May 2016 

Since last week, WHO AFRO reported that sequencing of the Zika virus in Cape Verde by Institut Pasteur in Dakar confirmed that the virus currently circulating in Cape Verde is the same as the one circulating in the Americas - the Asian type- and was most likely imported from Brazil. This is the first time that the Asian Zika strain has been detected in Africa.

 

In Brazil, the Ministry of Health informed the International Olympic Committee about the measures being taken to prevent and control Zika virus infections during the Olympics.

 

Publication

An article published in the New England Journal of Medicine suggests that 'although much remains unknown about the effects of ZIKV infection during pregnancy, population-level data from French Polynesia and Bahia reveal a clear association between first-trimester ZIKV infection and microcephaly risk'.

 

Table 1. Countries and territories with reported confirmed autochthonous cases of Zika virus infection in the past three months, as of 26 May 2016

 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.

EU/EEA and EU Outermost Regions and Territories

As of 26 May 2016, ECDC has recorded 638 imported cases in 18 EU/EEA countries. Thirty-six of the imported cases are pregnant women. In addition, one confirmed case was published following the diagnosis in a Slovenian hospital. The number of imported cases reported is not based on a systematic reporting surveillance systems hence cannot be considered exhaustive.

 

EU’s Outermost Regions and Territories  

• Martinique: As of 26 May 2016, 25 650 suspected cases have been reported, an increase of 1 100 since last week. Since the beginning of the outbreak to 26 May 2016, two microcephaly cases and one additional congenital abnormality have been reported with confirmed Zika virus infection. In addition, 20 cases with GBS have been detected. Among these, 19 have been confirmed with Zika virus infection.
• French Guiana: As of 26 May 2016, 6 700 suspected cases have been reported, an increase of 455 since last week. Three cases with neurological complications have been identified since the beginning of the outbreak.
• Guadeloupe: As of 26 May 2016, 6 320 suspected cases have been reported, an increase of 1 300 suspected cases since last week. One case with neurological complications has been reported since the beginning of the outbreak.
• St Martin: As of 26 May 2016, 425 suspected cases have been reported, an increase of 95 suspected cases since last week. One case with neurological complications has been reported. However, an association with Zika virus infection has not been established.
• St Barthélemy: As of 26 May 2016, 26 suspected and seven laboratory-confirmed case have been reported, an increase of ten suspected cases and six confirmed cases since last week. 

Figure 1. Countries or territories with reported confirmed autochthonous cases of Zika virus infection in the past three months, as of 26 May 2016 

Update on the observed increase of congenital Zika syndrome and other neurological complications

Congenital Zika Syndrome and GBS

In the context of Zika virus circulation, 13 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.

 

Brazil Since October 2015 and as of 21 May 2016, Brazil has reported 7 623 suspected cases of microcephaly and other nervous system disorders suggestive of congenital infection from 25 states in the federation. Of these cases, 1 434 are confirmed cases, 208 of which are laboratory-confirmed. This is an increase of 89 suspected cases and 48 confirmed cases of microcephaly with laboratory confirmed Zika virus infection since the last update on 14 May. Of the remaining cases, 2 932 were investigated and discarded as they did not meet the case definition, while 3 257 cases are still under investigation.

Colombia Between epidemiological weeks 1 to 19 in 2016, Colombia has reported five confirmed cases of microcephaly associated with Zika virus infection, 26 cases were discarded and 50 cases were still under investigation, according to the Ministry of Health.