Yellow fever in Brazil - ECDC assessment

23 January 2018

Article: 52/301

On 18 January 2018, the European Centre for Disease Prevention and Control (ECDC) issued a further assessment of the risk to EU/EEA countries and citizens associated with the on-going outbreak of yellow fever in Brazil.

The 2016-2017 yellow fever outbreak in Brazil was declared over in September 2017, yet the upsurge of human cases since December 2017 and non-human primate epizootics since September 2017 indicate a resurgence of yellow fever virus circulation in Brazil, particularly in São Paulo state. 

The detection of non-human primate cases in the vicinity of the metropolitan regions of São Paulo and Rio de Janeiro is of concern, particularly in light of the start of the mosquito activity season in December 2017 and the suboptimal vaccination coverage in some areas. There is an increased likelihood of peri-urban or urban cycles of yellow fever transmission, which significantly increases the number of potentially exposed people.

The Carnival, one of the largest international mass gatherings in Brazil, will take place from 9 to 14 February 2018. During the Carnival, the number of EU/EEA travellers to Brazil is expected to increase, hence the number of travel-related cases among unvaccinated travellers may increase in the coming months.

The risk of yellow fever importation and subsequent transmission in the continental EU/EEA is currently very low because the virus has to be introduced by viraemic travellers in an area with an established, competent and active mosquito vector population.

Further advice for clinicians advising travellers is available on the TRAVAX (for health professionals) and fitfortravel (for the general public) websites.

Source: ECDC Rapid Risk Assessment, 18 January 2018