Zika virus – Incidence and trends
To date, 47 countries and territories in the Americas have confirmed autochthonous, vectorborne transmission of Zika virus disease since 2015. In addition, five countries in the Americas have reported sexually transmitted Zika cases.2 Since the last Zika Epidemiological Update of 22 September 2016, no additional countries and/or territories have confirmed vector-borne autochthonous transmission of Zika virus in the Americas (Figure 1).
Highlighted below is a summary of the Zika epidemiological situation by sub-regions of the Americas.
North America
In Mexico, the downward trend of confirmed cases observed in the last 4 weeks, from epidemiological week (EW) 34 through EW 37, continues. In the United States of America, an increasing trend of confirmed cases is reported in the state of Florida.
Central America
In Central America, the trends of cases observed over the last four weeks in Costa Rica and Panama is described below.
The trend in Costa Rica has not varied much and continues to reflect a decrease in cases reported in the past four weeks; with a weekly average of cases reported during this period of 78 cases.
In Panama, following a sharp increase in cases between EW 30 and EW 35, reports for EW 36 and EW 37 show a decreasing trend. However, it remains to be seen if the decreasing trend continues.
Caribbean
In Anguilla, following a downward trend between EW 32 and EW 36, an increase was observed in EW 37 and 38. In the French overseas territories of Saint Barthelemy and Saint Martin, an increasing trend of suspected cases has been reported between EW 35 and EW 37. In Sint Maarten, an independent state within the Kingdom of the Netherlands, bordered to the north by the French territory of Saint Martin, an increase in confirmed cases has been reported in the last two weeks reported (EW 36 and EW 37). Puerto Rico continues to demonstrate a declining trend in cases since EW 35; this trend will continue to be monitored. Other countries/territories in the Caribbean also show a declining trend of Zika cases.
South America
In South America, all countries continue to report decreasing numbers of Zika cases.