Outbreak of yellow fever in Brazil
The 2016/2017 yellow fever outbreak in Brazil was declared over in September 2017. The upsurge of human cases since December 2017 and non-human primate epizootics since September 2017 indicates a resurgence of the circulation of yellow fever virus in Brazil, and more 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 Janeirois of concern, particularly in the light of the start of the mosquito activity season in December2017and the remaining sub-optimalvaccination coverage in some areas.
There is an increased likelihood of occurrence of peri-urban or urban cycleof yellow fever transmission, increasing drastically the population potentially exposed.