The Alabama Department of Public Health confirmed Tuesday four positive cases of Eastern Equine Encephalitis in horses located in Dallas County.

The confirmation comes the same day as the agency confirmed additional reports of EEE in horses in Elmore and Montgomery counties; however, laboratory confirmation has not been performed.

According to Dr. Dee W. Jones, State Public Health Veterinarian, the significance of positive horses and chickens means the virus is present in the mosquito population. He warns that the same mosquitoes that infect animals pose a risk to humans.

The confirmation of viral activity is very common in the summer and fall months. Positive case counts in the state vary from year to year based on mosquito populations. The virus can only be spread through the bite of a mosquito, and not from another animal.

“With many people enjoying outdoor activities, it is important that residents take every effort to reduce their exposure to mosquitoes,” Jones said. “Keep your mosquito repellent with you at all times when you are working or participating in recreational activities outdoors.”

EEE, WNV and other mosquito-borne viruses are transmitted by mosquitoes after they feed on birds. The same mosquitoes can then infect mammals, particularly humans and horses. Humans and horses can sometimes become seriously ill from the infection. Transmission to humans and horses can be decreased by persons taking steps to avoid mosquitoes and by the use of WNV and EEE vaccine in horses.

According to Jones, although there is no vaccine available for humans, vaccination for horses is very important in preventing infection in these animals.

Mosquitoes that can spread these viruses to humans are commonly found in urban and suburban communities as well as rural, freshwater swamp areas. They will breed readily in storm sewers, ditches, waste lagoons and artificial containers around houses.

It is important that homeowners do a careful inspection around their homes to be sure nothing holds water for longer than three days. In addition to surveillance activities, some county health departments also work to eliminate mosquito breeding sites and conduct larvicide and adulticide applications.

“It is reasonable to assume that mosquito-borne viruses are likely circulating between mosquitoes and birds in many parts of the state,” Jones said. “Everyone should try to avoid exposure to mosquitoes.”