Reservoir hosts experiencing food stress alter transmission dynamics for a zoonotic pathogen

Anthropogenic environmental change can significantly alter availability
and quality of food resources for reservoir hosts and impact host-pathogen
interactions in the wild. The state of the host’s nutritional reserves as
time of infection is a key factor influencing infection outcomes by
altering host resistance. Here we combine experimental and model-based
approaches to better understand how an environmental stressor affects host
resistance to West Nile virus (WNV). Using American robins (Turdus
migratorius), a species considered a superspreader of WNV, we tested the
effect of acute food deprivation immediately prior to infection on host
viremia. Our results show that robins food deprived of food for 48 hours
prior to infection, developed higher virus titers and were infectious
longer than robins fed normally. To gain understanding about the
epidemiological significance of food stressed hosts, we developed an
agent-based model that simulates transmission dynamics of WNV between the
avian reservoir host and the mosquito vector. When we simulated a
nutritionally stressed host population, the mosquito infection rate rose
significantly reaching levels that represent an epidemiological risk. An
understanding of the infection disease dynamics in wild populations is
critical to predict and predict and mitigate zoonotic disease outbreaks.