Situation summary in the Americas
Between January 2016 and December 2017, seven countries and territories of the Region of the Americas reported confirmed cases of yellow fever: the Plurinational State of Bolivia, Brazil, Colombia, Ecuador, French Guiana, Peru, and Suriname. The number of human cases and epizootics collectively reported in this period in the Region of the Americas is the highest observed in decades. The observed increase is as much related to an ecosystem favorable to the dissemination of the virus as to the unimmunized populations.
Since the 27 October 2017 Epidemiological Update on Yellow Fever published by the Pan American Health Organization / World Health Organization (PAHO/WHO), Brazil and Peru have reported new yellow fever cases. A summary of the situation in both countries is provided below.
In Brazil, following the yellow fever outbreak reported between the second semester of 2016 and June 2017, during which 779 confirmed cases, 262 deaths, and 1,659 epizootics were reported, there was a period with low transmission in humans. Confirmed cases were reported in epidemiological week (EW) 28, EW 38, and EW 40 of 2017, in São Paulo (2 cases) and in Rio de Janeiro state (1 case). For the cases confirmed in São Paulo state, one in EW 38 and the other in EW 40 (a fatal case in a 76-year-old man), Itatiba municipality was the probable site of infection. Guapimirim municipality was the probable site of infection of the case reported in Rio de Janeiro state. Figure 1 shows the distribution of confirmed cases in the country from EW 1 of 2016 to EW 49 of 2017.
In addition, Brazil authorities reported a case under investigation with probable site of infection in Brasilia, Federal District, in an area of epizootic occurrence; as well as, two cases under investigation in the state of Rio Grande do Sul and two others in Santa Catarina. Another 37 cases are under investigation in various states.
Considering that a decade ago, the outbreak of yellow fever and the epizootic wave that had affected southeastern and southern Brazil had subsequently reached Argentina and Paraguay, it is necessary to closely monitor the yellow fever situation in the south and southeast of Brazil during the 2017-2018 period.