About West Nile
The West Nile virus (WNv) is a mosquito-borne virus that can cause swelling and inflammation of the brain and spinal cord in horses, birds and humans.
The virus is named after the West Nile region of Uganda, where the virus first appeared in 1937. Since the discovery of WNv, it has become widespread in Africa and Eurasia. WNv was identified in the New York area in 1999, and has since become established across the North American continent.
Over 140 species of wild and domestic birds can be infected with WNv. As well, a wide range of wild and domestic animals can also be infected with WNv, including bears, mountain sheep and goats, horses, mules, donkeys, cattle, alpaca, dogs and cats. However, it is important to understand that disease is rare in the majority of these species. Only domestic geese, horses, mules and donkeys appear to be severely affected by WNv, and may develop clinical disease.
