(WNV) is a member of the Japanese
encephalitis virus serocomplex in the genus Flavivrus. It is maintained
in an enzootic transmission cycle between wild birds and Culex mosquitoes.
Since the introduction of (WNV) into the USA, (WNV antibodies) have been detected
in more than 150 species of birds, a large array of mammals, and a few amphibians/reptiles.
Disease has been pimarily observed in humans, horses and birds. Serology is
the key test for diagnosis of (WNV) in horses. IgM rises sharply and falls
during the first 6-8 weeks after exposure. Neutralizing antibody titers(primarily
IgG) devilop slowly during this time and stay elevated for several months.
The IgM capture (ELISA) is the test of choice for detection of recent exposure to
the virus.
