There is an ongoing outbreak of yellow fever in Brazil. Between 1 July 2017 and 13 March 2018, 920 confirmed human cases of yellow fever have been reported in Brazil, including 300 deaths; in Minas Gerais (415 cases, 130 death), São Paolo (376 cases, 120 deaths), Rio de Janeiro (123 cases, 49 deaths), Espirito Santo (5 cases) and Distrito Federal (1case, 1 death).
As a result, Yellow fever vaccination recommendations have been revised by the World Health Organization (WHO) based on the risk assessment of yellow fever transmission. The updated areas at risk for yellow fever are available on the WHO ITH website: http://www.who.int/ith/updates/20180116/en/.
WHO, considering the increased level of yellow fever virus activity observed across the state of São Paulo, decided that the entire state of São Paulo should currently be considered at risk of yellow fever transmission and vaccination against yellow fever is recommended for international travelers visiting any area in the state of São Paulo.
Cases of yellow fever in unvaccinated travelers who traveled to risk areas in Brazil have also been reported recently in: the United Kingdom (1), France (1), the Netherlands (1), Argentina (4), Chile (3), Romania (1) and Switzerland (1). Probable site of infection for these cases are under investigation and include Mairiporã/Atibaia, São Paolo (1 case), Ilha Grande/Angra do Reis, Rio de Janeiro (8 cases), Brumadinho, Minas Gerais (1 case).
Travelers should be informed that yellow fever is transmitted to humans via the bite of an infected mosquito and should take insect bite avoidance measures.
Vaccination against yellow fever is recommended for all travelers ≥9 months of age at least 10 days prior to the travel when visiting areas where there is a risk of yellow fever transmission. A single dose of WHO approved yellow fever vaccine is sufficient to provide sustain immunity and life-long protection against the disease, and a booster dose of the vaccine is not required.
Travelers should also be aware of symptoms and signs of yellow fever and immediately seek care while traveling and upon return from areas at risk for yellow fever transmission.
WHO does not recommend the implementation of any general travel or trade restriction.