West Nile Virus

West Nile virus belongs to the group of viruses known as 'arboviruses' or arthropod-borne viruses, so-called as they are transmitted by arthropods (insects such as mosquitoes and ticks). The mosquitoes involved in the transmission of West Nile virus usually feed on birds but will sometimes bite and infect horses or humans.

West Nile virus has been found in Africa, Europe, the Middle East, west and central Asia, and more recently, North America. Sporadic cases and outbreaks of disease in humans and horses have occurred in Europe since the 1960s.