Situation summary in the Americas
Since epidemiological week (EW) 1 to EW 19 of 2017, Brazil, Colombia, Ecuador, Peru, the Plurinational State of Bolivia, and Suriname have reported suspected and confirmed yellow fever cases.
The following is an update on the situation in Brazil. The situation in the other countries was reported in the epidemiological update of 25 April 2017 and in previous updates, and no significant changes have been reported since then.
In Brazil, since the beginning of the outbreak in December 2016 up to 18 May 2017, there were 3,192 suspected cases of yellow fever reported (758 confirmed, 1,812 discarded, and 622 remain under investigation), including 426 deaths (264 confirmed, 120 discarded, and 42 under investigation). The case fatality rate (CFR) among confirmed cases is 34%.
According to the probable site of infection,1 the cases were reported in 398 municipalities, while the confirmed cases were distributed among 131 municipalities in 7 states (Espírito Santo, Goiás, Minas Gerais, Pará, Rio de Janeiro, São Paulo, and Tocantins).
With regard to the confirmed fatal cases and their probable site of infection, 80 were in Espírito Santo, 1 in Goiás, 164 in Minas Gerais, 4 in Pará, 5 in Rio de Janeiro, and 10 in São Paulo. In the states with more than 5 confirmed deaths, the CFR among confirmed cases is 50% in São Paulo, 35% in Rio de Janeiro, 34% in Minas Gerais and Espírito Santo.
No cases or epizootics were confirmed in new municipalities in Espírito Santo (ES), Minas Gerais (MG), and São Paulo (SP) in the last two weeks. The dates of symptoms onset of the most recently confirmed cases are 14 March 2017 (MG), 19 April (SP), and 24 April (ES).
The state of Pará continues to report four confirmed cases in EW 13 of 2017, and the state of Tocantins reported a confirmed case in EW 16 of 2017. In addition, a case was confirmed in the state of Goiás in an area known to be at risk for yellow fever.
Although no confirmed cases have been reported to date in the state of Bahia, since the beginning of the year up to 8 May 2017, a total of 255 epizootics were reported in 78 municipalities; 54 of these epizootics were positive for yellow fever by RT-PCR in 28 municipalities, and 4 were in neighborhoods of Salvador.
To date, the Aedes aegypti vector has not been reported to have a role in transmission. However, confirmed epizootics in large cities, such as Vitoria in Espírito Santo4 and Salvador in Bahia,3 represent a high risk for a change in the transmission cycle.