Deep behavioral phenotyping of pathogen infected mosquitoes reveals species-specific behavior changes enhancing transmission

Abstract

Mosquito-borne pathogens are often proposed to alter mosquito behavior to enhance transmission, yet the prevalence, magnitude, and consequences of such effects remain unclear. Using custom high- throughput behavioral assays and deep-learning analysis, we quantified the blood-feeding behavior of more than 5,000 mosquitoes, and long-term activity patterns of more than 1,000 mosquitoes across six clinically relevant mosquito-pathogen combinations. Infection effects were highly species-specific. Anopheles stephensi infected with an African Plasmodium falciparum strain showed elevated flight activity throughout infection, an increased tendency to blood-feed upon host contact, and prolonged feeding times. In contrast, infection with an Asian P. falciparum strain or P. vivax had little impact on An. stephensi behavior. We detected no behavioral changes associated with P. falciparum infection in Anopheles gambiae s.s. or Anopheles coluzzii. Interestingly, dengue virus infection in Aedes aegypti increased landing, probing, and engorgement rates. Together, these results demonstrate that infection-induced behavioral change is not a general phenomenon among mosquito-borne pathogens, yet differs markedly per mosquito and pathogen species. A transmission model parameterized with our data showed that even modest behavioral shifts can substantially increase transmission, underscoring the potential epidemiological importance of subtle phenotypic shifts.