Epidemiological Update - Zika Virus Infection - 26 July 2017

Situation summary in the Americas

Since epidemiological week (EW) 44 of 2016, no additional countries or territories of the Americas have confirmed autochthonous, vector-borne transmission of Zika virus disease. To date, 48 countries and territories in the Americas have confirmed autochthonous, vectorborne transmission of Zika virus disease,while five countries have reported sexually transmitted Zika cases.

The following is a summary of the epidemiological situation by sub-regions.

North America

In the United States of America, the Florida Department of Health reported that Florida no longer has any identified areas with active Zika transmission, and cases of local transmission have not been reported in 2017. Similarly, cases of local transmission have not been reported in Texas during 2017.

In Mexico, although confirmed cases continue to be reported, the trend has been declining since EW 40 of 2016. In EW 27 of 2017, local transmission of Zika virus was confirmed in Mexico State.

Central America

The trend of reported cases in Central America remains stable with a weekly average of 70 suspected and confirmed cases between EW 15 and EW 25 of 2017 (Figure 2), with the exception of Costa Rica, where an increase in the number of suspected and confirmed Zika cases was observed between EW 16 and EW 26 of 2017.

Caribbean

In countries/territories of this sub region, sporadic cases continue to be reported, with a weekly average of 291 suspected and confirmed cases reported between EW 15 and EW 25 of 2017. In Puerto Rico, the trend of cases observed in the last 8 weeks is decreasing.

South America

From EW 1 to EW 14 of 2017, an increasing trend of suspected and confirmed cases was observed in South America, mainly due to increases in the number of reported cases in Argentina, Bolivia (Plurinational State of), Brazil, Ecuador, and Peru (Figure 3). Between EW 15 and EW 25 of 2017, an average of 863 suspected and confirmed cases were reported per week in this sub-region.

In Argentina, an increase in suspected and confirmed cases was observed between EW 1 and EW 16 of 2017; this increase was related to outbreaks in the provinces of Formosa, Salta, and Chaco. In these latter two provinces, the date of symptom onset of the last confirmed cases was EW 20 and EW 16 of 2017, respectively.