Yellow fever in Brazil: confirmed cases in urban areas in São Paulo and Rio de Janeiro

News Epidemiological update

From July to October 2017 the Brazilian authorities reported three confirmed human cases of yellow fever - one in Rio de Janeiro and two in São Paulo State. One person died. In addition, several animal cases were detected in the urban area of São Paulo City. The national health authorities have started a vaccination campaign in São Paulo State.

Brazil experienced a major outbreak of yellow fever in 2016 and few confirmed cases have been reported in 2017. However, no cases have been previously reported in the city of São Paulo.

The newly reported human cases in São Paulo State and the animal cases in the city of São Paulo, not previously considered as an area at risk, is of concern.

The city of São Paulo has a population of 10 million inhabitants and the number of unvaccinated people is high. Aedes aegypti, the primary mosquito vector of yellow fever in urban settings, is present in São Paulo.

According to the World Health Organization, travellers planning to visit areas at risk for yellow fever in Brazil should receive yellow fever vaccine at least 10 days prior to travelling, should follow measures to avoid mosquito bites, and should be aware of yellow fever symptoms and signs.

Within the EU/EEA, the risk of yellow fever transmission is currently considered to be very low, as stated in the latest ECDC risk assessment. Travellers to areas at risk of yellow fever in Brazil and other countries in South America should be aware of the risk and should check their vaccination status.

Yellow fever is a mosquito-borne infection, endemic in Africa and South America. In severe cases there may be spontaneous haemorrhage and mortality can be as high as 80%.