The Florida Department of Health in Orange County says several of its sentinel chickens, which are placed throughout the area, tested positive for Eastern equine encephalitis (EEE).
EEE is a rare, but serious infection that is spread by the bite of an infected mosquito. The disease can cause encephalitis or swelling of the brain and sometimes be fatal. About 30 percent of people who contract EEE die, according to the CDC. About seven cases in humans are reported each year.
Symptoms appear about 4 to 10 days post-infection and can include high fever, chills, vomiting and sudden onset of headache as well as disorientation, seizures and coma. Many survivors will experience ongoing neurological problems, according to the CDC. The disease can also infect a number of animals, including mammals, reptiles and birds.
Sentinel chickens are often tested for EEE, as well as the West Nile virus, but they do not suffer from the effects of the virus.
Experts say the best way to prevent mosquito-born viruses are by getting rid of standing water around the home and in the yard, using screens to cover doors and windows, covering skin with clothing or repellent and avoiding the outdoors between dusk and dawn.