Mosquito Life-History Responses to Vector control Measures and their implications for Malaria Tansmission Risk

Malaria is transmitted by Anopheles mosquitoes and kills >600,000 people every year, mainly in Africa. The fight against malaria using insecticides against the mosquito vector is one of the most effective measures to reduce malaria risk, but it could be under severe risk due to increasing insecticide resistance among the vector population. However, to understand and manage the risks associated to the potential decreasing effectiveness of vector control on disease transmission, it is essential to comprehend all the possible evolutionary consequences of these strategies. Despite the crucial importance on malaria transmission potential, nothing is known about vector control impact on mosquito life-history trait evolution. With AXA Research Fund’s support, Dr. Francesco Baldini will work to fill this critically important knowledge gap and test how current measures can induce mosquito life-history shifts that can drastically modify their ability to transmit malaria. Specifically, as predicted by life-history theory, through the increase of extrinsic-mortality rates, vector control measures could generate selection for mosquitoes with reduced intrinsic-survival and increased earlier reproduction, which could significantly alter their disease transmission potential.

Furthermore, the harsh environment experienced by adult mosquitoes can modify maternal reproductive strategies and alter offspring fitness potentially influencing their vectoral capacity. Dr. Baldini proposes to perform a series of experimental investigations on the major African malaria vector An. gambiae, to assess the short- and long-term responses on mosquito life-history traits by conditions associated with vector control, and their impact on the ability to transmit human malaria parasites. He will also analyze the molecular bases of possible trade-offs imposed by vector control, such as those between survival and reproduction, possibly allowing the design of putative markers for monitoring evolutionary shifts in the field. He proposes to perform these ecological, evolutionary and infection studies collaborating with international leaders in the fields of mosquito vector ecology and malaria population genetics at the University of Glasgow in a dynamic, multidisciplinary and collaborative research environment. This study will start to elucidate the potential long-term effectiveness of current malaria control measures in order to sustain and implement future interventions to reduce malaria transmission risk.