# Consequences of pathogen co-infection in mosquitoes on West Nile virus transmission

> **NIH NIH K01** · TEXAS A&M AGRILIFE RESEARCH · 2020 · $107,149

## Abstract

PROJECT SUMMARY/ABSTRACT
Occurring on every continent except Antarctica, West Nile virus (WNV) is the most
widely distributed zoonotic arthropod-borne virus (arbovirus) resulting in an estimated
780,000 human illnesses and 1,549 deaths in the U.S. since 1999. WNV is maintained
in a Culex mosquito and bird enzootic transmission cycle which is the same cycle for a
suite of other parasites and pathogens. As a result, the Culex mosquitoes responsible
for enzootic transmission and bridge transmission to humans are frequently exposed to
a variety of other parasites and pathogens. Prior studies have demonstrated that co-
infections of multiple pathogens in insects can result in direct and immune-mediated
interactions. In mosquitoes, these interactions could have important consequences on
the ability of an arbovirus to replicate and infect the salivary glands (i.e. vector
competence). Additionally, co-infections could influence survival or the time it takes for
the virus to reach the salivary glands (i.e. extrinsic incubation period) which are
important parameters in the model that describes the number of new hosts exposed to a
pathogen by a specified population of mosquitoes per infected host per day (i.e. vectorial
capacity). The goal of this proposal is to 1) evaluate the consequences of pathogen
interactions on WNV vector competence and vectorial capacity and 2) apply
epidemiological models to assess the ability of co-circulating parasites to impact the
reproductive number (R0) of WNV in nature. Using laboratory infection experiments in
Culex mosquitoes, we will test the hypothesis that co-infections with Plasmodium or an
insect-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 in
nature. Although these common parasites and pathogens may not directly cause human
disease, I anticipate highlighting the potential for these pathogens to affect human health
indirectly, by driving dynamics of WNV. During this award, the Principal Investigator
(PI) will receive structured training in virology, vector competence, and mathematical
modeling and will then apply those skills to the research outlined here. This award will
provide a foundation to help the PI achieve his career goals of understanding
mechanisms of arboviral transmission to develop improved interventions aimed at
mitigating human and animal disease.

## Key facts

- **NIH application ID:** 9842644
- **Project number:** 5K01AI128005-04
- **Recipient organization:** TEXAS A&M AGRILIFE RESEARCH
- **Principal Investigator:** Gabriel Lee Hamer
- **Activity code:** K01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $107,149
- **Award type:** 5
- **Project period:** 2017-01-01 → 2021-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9842644

## Citation

> US National Institutes of Health, RePORTER application 9842644, Consequences of pathogen co-infection in mosquitoes on West Nile virus transmission (5K01AI128005-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9842644. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*