Thursday, August 6, 2009 - 8:55 AM

SYMP 17-3: Vector feeding patterns and the transmission of multi-host pathogens

A. Marm Kilpatrick, University of California, Santa Cruz, Juliet R. C. Pulliam, Fogarty International Center, National Institutes of Health, Matthew J. Jones, New York State Department of Health, Peter Marra, Smithsonian Migratory Bird Center, Peter Daszak, The Consortium for Conservation Medicine, and Laura D. Kramer, Wadsworth Center, New York State Dept Health and SUNY Albany.

Background/Question/Methods

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.