Effect of prolonged dehydration stress on the vector competence of Aedes aegypti for Mayaro virus

Aedes aegypti is a competent vector for a variety of mosquito-borne viruses including Zika, chikungunya, Mayaro, yellow fever, and dengue, which cause debilitating diseases in animals and humans. It is highly invasive and is widely distributed across Asia, Europe, Oceania, and the Americas. Climatic factors such as relative humidity (RH) can have substantial effects on mosquito biological characteristics and the dynamics of pathogen spread. Low RH leads to dehydration in mosquitoes causing modifications in behavioral and physiological responses pertaining to pathogen spread, such as host-seeking behavior and blood-feeding patterns. Here, we evaluated the effects of prolonged dehydration stress on Mayaro virus infection and vector competence in Ae. aegypti mosquitoes. Our findings suggest that prolonged dehydration stress following Mayaro virus infection alters viral dissemination dynamics in mosquitoes, indicating that humidity may modulate intra-vector viral dissemination potentially impacting vector competence and pathogen spread. The previously observed effects of higher feeding and altered survival and our current observations on altered vector competence suggest that the impact of dehydration on viral transmission is expected to be complex and will be crucial to understanding the dynamic disease patterns of mosquito-borne viruses across diverse climatic conditions.