The importance of vector feeding habits for multi-host pathogens cannot be understated, as they determine which hosts are infected, who infects the vectors, and as a result, they play a large role in regulating the intensity of pathogen transmission.  Patterns of feeding are likely dependent on vector preferences (which may have a genetic basis) as well as host availability.  However, two other transmission modes (vertical transmission and co-feeding) may be important for some pathogens.

Results/Conclusions

I will present data on the feeding patterns of mosquitoes across a large geographical area to compare the relative importance of different hosts in amplifying West Nile virus, the importance of co-feeding on competent and incompetent hosts, and the magnitude of vertical transmission necessary for it to make a meaningful contribution to viral amplification.  Surprisingly, despite infection and feeding on >100 hosts, a single host appears to be the dominant amplification host for West Nile virus across large regions of the USA, and variable feeding on this host may be playing a key role in both the rise and fall in West Nile virus prevalence in mosquitoes.  Co-feeding and vertical transmission are unlikely to be important in the seasonal transmission of West Nile virus, but the latter may be important in overwintering of the virus.