How do mosquitoes become infected with West Nile Virus?
Mosquitoes become infected with WNV when they feed on birds that are infected with WNV. After a few days, infected mosquitoes can then transmit WNV to other birds, humans and horses. Only certain species of mosquitoes carry the virus. Culex mosquitoes are the main carriers of WNV, and these mosquitoes are common throughout Arizona. Culex mosquitoes tend to bite from dusk to dawn.
