Consequences of Pathogen Co-Infection in Mosquitoes on West Nile Virus Transmission | Grant individual record
date/time interval
2017 - 2020
PROJECT SUMMARY/Occurring on every continent except Antarctica, West Nile virus (WNV) is the mostwidely distributed zoonotic arthropod-borne virus (arbovirus) resulting in an estimated780,000 human illnesses and 1,549 deaths in the U.S. since 1999. WNV is maintainedin a Culex mosquito and bird enzootic transmission cycle which is the same cycle for asuite of other parasites and pathogens. As a result, the Culex mosquitoes responsiblefor enzootic transmission and bridge transmission to humans are frequently exposed toa variety of other parasites and pathogens. Prior studies have demonstrated that co-infections of multiple pathogens in insects can result in direct and immune-mediatedinteractions. In mosquitoes, these interactions could have important consequences onthe ability of an arbovirus to replicate and infect the salivary glands (i.e. vectorcompetence). Additionally, co-infections could influence survival or the time it takes forthe virus to reach the salivary glands (i.e. extrinsic incubation period) which areimportant parameters in the model that describes the number of new hosts exposed to apathogen by a specified population of mosquitoes per infected host per day (i.e. vectorialcapacity). The goal of this proposal is to 1) evaluate the consequences of pathogeninteractions on WNV vector competence and vectorial capacity and 2) applyepidemiological models to assess the ability of co-circulating parasites to impact thereproductive number (R0) of WNV in nature. Using laboratory infection experiments inCulex mosquitoes, we will test the hypothesis that co-infections with Plasmodium or aninsect-specific flavivirus will significantly increase or decrease WNV vectorial capacity.At the completion of these studies, it is my expectation to have identified specific co-circulating pathogens that have important consequences for WNV transmission innature. Although these common parasites and pathogens may not directly cause humandisease, I anticipate highlighting the potential for these pathogens to affect human healthindirectly, by driving dynamics of WNV. During this award, the Principal Investigator(PI) will receive structured training in virology, vector competence, and mathematicalmodeling and will then apply those skills to the research outlined here. This award willprovide a foundation to help the PI achieve his career goals of understandingmechanisms of arboviral transmission to develop improved interventions aimed atmitigating human and animal disease.