As many as seven countries– Afghanistan, Iraq, Libya, Somalia, Sudan and Syria in the WHO Eastern Mediterranean Region have established an early warning system for disease outbreaks with a view to early detecting and rapidly investigating any public health event of potential concern. Such a system, in the absence of a routine disease surveillance system, needs continuous monitoring and assessment using a set of performance benchmarks.
The 2016/2017 yellow fever outbreak in Brazil was declared over in
September 201, 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 no-human primatecases 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 suboptimalvaccination 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.