A mosquito-born viral disease. The EEE virus normally is found in freshwater swamp birds and mosquitoes that do not bite people. However, the virus is occasionally transmitted to other types of mosquitoes capable of biting horses and people. The risk of contracting EEE is highest in mid-to-late summer. The mosquitoes are killed by frost.
Symptoms: The first symptoms are fever (103-106F), stiff neck, and headache starting 2-10 days after infection. Swelling of the brain (encephalitis) is the most feared feature. The disease gets worse quickly, and many patients go into a coma within a week and some die. Those who survive suffer mild to severe neurologic deficits. Very few people recover completely.
Prevention: The disease can be prevented in horses with the use of vaccinations. These vaccinations are usually given together with vaccinations for other diseases, most commonly WEE, VEE, and tetanus. Most vaccinations for EEE consist of the killed virus.
Treament: There is no cure for EEE. Treatment consists of corticosteroids, anticonvulsants, and supportive measures such as intravenous fluids, tracheal intubation, and antipyretics.
Epidemology: In 2006, approximately 500,000 acres (2,000 km2) in southeastern Massachusetts were treated with mosquito adulticides to reduce the risk of humans contracting EEE. There have been several human cases reported in New Hampshire as well.