Sumario: |
The influence of host diversity on multi-host pathogen transmission and persistence can be confounded by the large
number of species and biological interactions that can characterize many transmission systems. For vector-borne
pathogens, the composition of host communities has been hypothesized to affect transmission; however, the specific
characteristics of host communities that affect transmission remain largely unknown. We tested the hypothesis that vector
host use and force of infection (i.e., the summed number of infectious mosquitoes resulting from feeding upon each
vertebrate host within a community of hosts), and not simply host diversity or richness, determine local infection rates of
West Nile virus (WNV) in mosquito vectors. In suburban Chicago, Illinois, USA, we estimated community force of infection for
West Nile virus using data on Culex pipiens mosquito host selection and WNV vertebrate reservoir competence for each host
species in multiple residential and semi-natural study sites. We found host community force of infection interacted with
avian diversity to influence WNV infection in Culex mosquitoes across the study area. Two avian species, the American robin
(Turdus migratorius) and the house sparrow (Passer domesticus), produced 95.8% of the infectious Cx. pipiens mosquitoes
and showed a significant positive association with WNV infection in Culex spp. mosquitoes. Therefore, indices of community
structure, such as species diversity or richness, may not be reliable indicators of transmission risk at fine spatial scales in
vector-borne disease systems. Rather, robust assessment of local transmission risk should incorporate heterogeneity in
vector host feeding and variation in vertebrate reservoir competence at the spatial scale of vector-host interaction.
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