Changes in West Nile virus seroprevalence and antibody titers among Wisconsin mesopredators 2003-2006.
After the 2001 occurrence of West Nile virus (WNV) in Wisconsin (WI), we collected sera, during 2003-2006, from south-central WI mesopredators. We tested these sera to determine WNV antibody prevalence and geometric mean antibody titer (GMAT). Four-fold higher antibody prevalence and 2-fold higher GMAT in 2003-2004 indicated greater exposure of mesopredators to WNV during the apparent epizootic phase. The period 2005-2006 was likely the enzootic phase because WNV antibody prevalence fell to a level similar to other flaviviruses. Our results suggest that, in mesopredators, vector-borne transmission is the primary route of infection and WNV antibodies persist for < 1 year. Mesopredators may be sensitive indicators of West Nile virus spill-over into humans and horses. Mesopredator sero-surveys may complement dead crow surveillance by providing additional data for the timing of public health interventions. Research is needed to clarify the dynamics of WNV infection in these mammals and their role as potential WNV amplifiers.
Docherty
Douglas E
DE
United States Geological Survey, National Wildlife Health Center, Madison, Wisconsin 53711, USA. ddocherty@usgs.gov
Samuel
Michael D
MD
Egstad
Kristina F
KF
Griffin
Kathryn M
KM
Nolden
Cherrie A
CA
Karwal
Lovkesh
L
Ip
Hon S
HS
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D046029:Coyotes / Q000821:virology*; D009893:Opossums / Q000821:virology*; D011821:Raccoons / Q000821:virology*; D016036:Seroepidemiologic Studies; D013997:Time Factors; D014902:West Nile virus / Q000276:immunology*; D014922:Wisconsin / Q000453:epidemiology
D000914:Antibodies, Viral