During the outbreak several thousand birds died from the virus, crows were the hardest hit. Dead crows were also found in Connecticut and New Jersey. Infected migrant birds were found as far south as Maryland. To date the virus has been found in 11 states and the District of Columbia. Virus cycle Mosquitoes become infected with the virus when they obtain a blood meal from an infected bird.
Infected birds are able to provide the virus to mosquitoes for several days.
During this time they may infect many mosquitoes. Once a mosquito has blood fed on an infected bird the virus incubates in the mosquito for up to two weeks. These infected mosquitoes may then pass the virus on to a person or another bird. A variety of mosquito species have been found to be carrying the virus. Most often the virus has been found in Culex pipiens , Cx. restuans and Cx. salinarius .