The primary cause of the West Nile virus can be traced back to mosquitoes. These insects seem to be the main source of virus transmission to humans. Although the virus may have been carried from place to place by birds, it is the mosquitoes that eventually transfer the virus to humans. A mosquito that bites a bird infected by the West Nile virus becomes a carrier. Once an infected mosquito bites a human, the virus is then transferred into humans. The best way of avoiding the transmission of the …