Where Does EEE Come From?
EEE virus occurs naturally in a wide variety of wild song birds. Blood samples from New Jersey birds indicate that Blue Jay, Wood Thrush, Tufted Titmouse, Chickadee, Catbird and Cardinal show the highest incidence of infection in our state. EEE virus normally appears in local bird populations shortly after the nesting season is over in the spring. Mosquitoes transmit the infection from bird to bird during the early summer months and infections usually peak sometime in August. In some years, the virus remains in local bird populations and does not pose a health threat to horses or humans. When mosquito populations are high, however, transfer from birds to horses and/or humans is possible. In a typical outbreak year, horse cases begin to appear in unvaccinated animals in mid-summer. All equine cases are the result of mosquitoes which have fed on infected birds and then feed on unvaccinated horses.
