: The introduction of exotic arboviruses into new ecological niches has occurred with increasing frequency in recent years, presenting an ongoing challenge to the public health and biodefense communities. RNA viruses, such as West Nile virus, Dengue virus, Rift Valley fever virus and Venezuelan Equine Encephalitis virus, exist within each host as a genetically diverse swarm of competing genotypes that has been termed quasispecies. The quasispecies structure of arbovirus populations allows rapid adaptation of these agents upon inadvertent or deliberate introduction to a new ecological niche. Quantitative measures of the quasispecies nature of zoonotic arbovirus populations in nature do not exist. Further, the impact of transmission by an arthropod on the viral quasispecies has not been adequately assessed. The proposed research will combine field- and laboratory-derived observations to examine the population-level mechanisms of genetic change that may occur when a new arbovirus is introduced into a halve ecosystem. To determine whether the quasispecies structure of arboviruses may promote viral adaptation and disease emergence, proposed research will (a) characterize the quasispecies structure of enzootically transmitted West Nile virus (WNV) and (b) determine whether WNV genetic diversity is generated or constrained in mosquitoes and birds.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AI055609-02
Application #
6780426
Study Section
Special Emphasis Panel (ZRG1-TMP (99))
Program Officer
Repik, Patricia M
Project Start
2003-08-01
Project End
2006-07-31
Budget Start
2004-08-01
Budget End
2006-07-31
Support Year
2
Fiscal Year
2004
Total Cost
$243,594
Indirect Cost
Name
Wadsworth Center
Department
Type
DUNS #
153695478
City
Menands
State
NY
Country
United States
Zip Code
12204
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Jerzak, Greta V S; Brown, Ivy; Shi, Pei-Yong et al. (2008) Genetic diversity and purifying selection in West Nile virus populations are maintained during host switching. Virology 374:256-60
Jerzak, Greta V S; Bernard, Kristen; Kramer, Laura D et al. (2007) The West Nile virus mutant spectrum is host-dependant and a determinant of mortality in mice. Virology 360:469-76
Jerzak, Greta; Bernard, Kristen A; Kramer, Laura D et al. (2005) Genetic variation in West Nile virus from naturally infected mosquitoes and birds suggests quasispecies structure and strong purifying selection. J Gen Virol 86:2175-83