Eastern Equine Encephalitis

What Is Eastern Equine Encephalitis ?

Eastern Equine Encephalitis (EEE) is a viral illness that can cause inflammation of the brain. Certain birds are reservoirs for this virus; mosquitoes that feed on these birds can carry the virus to people and other animals. Similar to West Nile Virus and St. Louis Encephalitis, a mosquito that bites an infected bird can in turn bite a mammal or a person. EEE can produce severe disease in horses, some game birds and rarely, people. Most cases of EEE in the United States occur in east coast and gulf coast states.

The Eastern Equine Encephalitis (EEE) virus (togavirus family) has long been recognized in the United States, though fewer than 160 cases have been reported in humans in this country in the past 35 years.

However, hundreds of equine cases have been reported in South Carolina, and EEE virus has also been isolated from birds and mosquitoes.

What are the symptoms?

Progress of the disease is very rapid. Symptoms range from mild flu-like illness to encephalitis, coma and death.

How is Eastern Equine Encephalitis treated?

There is no specific cure for Eastern Equine Encephalitis. It is caused by a virus, so antibiotics won't help. In mild cases, physicians recommend the same remedies you would use for other viruses, such as the flu: drink plenty of water, resting in bed, drinking plenty of fluids, and taking medication such as acetaminophen or ibuprofen to relieve fever and discomfort. In more severe cases treatment may include hospitalization, intravenous fluids, and perhaps even intensive care.

Anyone experiencing severe or unusual headaches should see a doctor as soon as possible. Also, anyone who has been in an area where the virus has been identified and who experiences high fever, muscle weakness, confusion or severe headaches should see a doctor immediately.

How do people catch this disease?

Eastern Equine Encephalitis cannot be passed from person to person. The only way to get the virus is from the bite of an infected mosquito that has the virus in their blood. The mosquito can spread the virus to birds, animals or people, when it bites during feeding. Transmission to people and mammals is rare, but can be serious when it occurs.

How can we prevent this illness?

There are many things that you can do to help. Reducing the breeding grounds for mosquitoes is vital to preventing mosquito-transmitted diseases.

Be sure to empty any and all containers that hold standing water, and keep them emptied.

You can reduce the possibility of this infection even more by taking a few other simple steps:

  • Wear long sleeved shirts and long pants when you go outside
  • Stay inside at mosquito feeding time; dawn, dusk and early evening
  • Spray clothing with a mosquito repellant containing DEET
  • Apply insect repellant containing DEET to exposed skin
  • There is a vaccine available for horses. For more information, contact your veterinarian

References and Additional Information

Protect Yourself from Mosquito Bites (DHEC)


Health Infectious Diseases