Brazilian authorities launch vaccination effort to prevent widespread yellow fever outbreak

With 35 confirmed cases of yellow fever and 20 deaths reported in Brazil from July 1, 2017, through Jan. 14, public health officials have launched an intensive vaccination campaign in an effort to head-off a widespread outbreak.

Yellow fever cases have been confirmed in São Paulo, Rio de Janeiro, Minas Gerais, and the Brazilian Federal District. An additional case was confirmed in the Netherlands after a traveler returned from Brazil. Another 145 suspected cases are currently under investigation in Brazil.

The World Health Organization (WHO) reports that the number of animals infected with yellow fever indicates a “high level of circulation” of the vector-borne virus in ecosystems favorable for transmission. Through Jan. 14, 2,442 epizootics were reported in primates, including some in areas previously considered to not be at an elevated risk.

“The large number of unvaccinated people who continue to live in areas with ecosystems favorable for transmission of the yellow fever virus represents an elevated risk for the change in the current transmission pattern,” WHO stated.

Ongoing vaccination efforts, coupled with measures taken during a 2016-2017 yellow fever outbreak, are expected to limit the transmission of yellow fever. WHO continues to recommend that international travelers be vaccinated before leaving for Brazil.