Epizootic propagation cycles of yellow fever virus in Brazil

Yellow fever virus (YFV) is an arbovirus transmitted by mosquitoes that maintains sylvatic cycles in neotropical primates and mosquitoes of the genera Haemagogus and Sabethes. In Brazil, human outbreaks result from viral amplification in susceptible primate populations, especially howler monkeys (Alouatta spp.). YFV spreads in epizootic waves originating in the Amazon and extends to extra-Amazonian biomes such as the Atlantic Forest. Viral dispersion is driven by the mobility of vector mosquitoes and shows seasonal variations. Recent events show greater territorial reach, possibly linked to environmental changes, highlighting the importance of surveillance in primates and human vaccination within the One Health approach.