West Nile Virus (WNV)


West Nile virus (WNV) is a rapidly spreading mosquito-borne disease. Wild birds are the reservoir that become infected via the mosquito, which acts as the vector. The mosquito infects birds, horses, humans and other species.

Symptoms range from nonexistent or mild to neuroinvasive, with up to 10% of infected horses exhibiting neurological symptoms—meningitis, encephalitis, paresis, motor neuron infections and flaccid paralysis—and a 20%–60% mortality rate in horses.

Though there is no specific treatment for WNV, detection is essential. A positive IgM antibody test indicates a horse had contact with the virus within the last three months, which means infected mosquitoes are circulating in the area and appropriate actions should be taken to protect animals and control or eliminate the mosquito population.

West Nile Virus

Testing Solutions




Availability/Distribution: Outside the U.S.

The IDEXX IgM WNV Ab Test detects IgM antibodies in serum or cerebrospinal fluid, which is very useful for epidemiological studies as well as the disease diagnosis because their presence indicates a recent infection of the host, (the IgM antibodies can be detected up to 3 months after infection). This ELISA detects specific West Nile IgM antibodies in horse sera and is an IgM capture ELISA as described in the OIE Terrestrial Manual.


IgM WNV Informational Sheet PDF icon

IgM WNV Informational Brochure PDF icon

IgM WNV Protocol Poster PDF icon

IgM WNV Protocol Reminder PDF icon


Part Number: P00730
(2 plates/strips)


† Not all products are available and/or registered in every country.