The emergence and global expansion of Aedes aegypti puts more than half of all humans at risk of arbovirus infection, but the origin of this mosquito and the impact of contemporary gene flow on arbovirus control are unclear. We sequenced 1206 genomes from 73 globally distributed locations. After evolving a preference for humans in Sahelian West Africa, the invasive subspecies Ae. aegypti aegypti ( Aaa ) emerged in the Americas after the Atlantic slave trade era and expanded globally. Recent back-to-Africa Aaa migration introduced insecticide resistance and anthropophily into regions with recent dengue outbreaks, raising concern that Aaa movement could increase arbovirus risk in urban Africa. These data underscore developing complexity in the fight against dengue, Zika, and chikungunya and provide a platform to further study this important mosquito vector.
Crawford et al. (2025) studied this question.