During acclimation, feral rats were determined to be seronegative for EEEV, VEEV, and western equine encephalitis virus
by 80% plaque-reduction neutralization tests ([PRNT.
This case cluster formed the WNV epicenter for California during 2007, was the largest mosquito-borne encephalitis virus outbreak in Kern County since the 1952 epidemic of western equine encephalitis virus
(5) and represented a 205% 280% increase in the numbers of confirmed WNV cases observed since 2004 (6).
Birds infected with western equine encephalitis virus
or Saint Louis encephalitis virus by mosquito bite or needle exhibit no difference in viremia responses (24), and mosquito saliva inhibits in vitro infection of dendritic cells by dengue virus (25).