Eastern equine encephalitis (EEE) virus is an illness caused by the bite of an infected mosquito. Only a few cases are reported in the United States each year, mostly in eastern or Gulf Coast states.
Although it is rare, EEE is very serious, and it can result in ongoing neurologic problems and death in about 30% of patients.
Signs and symptoms of EEE include:
- Febrile illness, which lasts about 1 to 2 weeks, and most people recover completely if there is no central nervous system involvement
- Fever
- Chills
- Body aches
- Joint pain
- Neurologic disease, which can include meningitis (infection of the membranes that surround the brain and spinal cord) and encephalitis (infection of the brain)
What Causes EEE?
Eastern equine encephalitis (EEE) is caused by a virus that is a member of the genus Alphavirus, family Togaviridae.
- EEE is transmitted to humans from the bite of an infected mosquito.
- There are a small number of reported cases in which the EEE virus was transmitted through organ transplantation from an infected donor.
How Is EEE Diagnosed?
Eastern equine encephalitis (EEE) is diagnosed with a patient history and physical examination, along with tests used to confirm the diagnosis, including:
- Blood tests
- Tests of spinal fluid
All cases of EEE virus disease should be reported to local public health authorities to enable local, state, and national authorities to recognize outbreaks of this rare disease and so control measures can be implemented to limit future infections.
What Is the Treatment for EEE?
There is no vaccine available to prevent eastern equine encephalitis (EEE), and there are no available antiviral treatments.
Treatment for EEE is aimed at relief of symptoms and may include:
- Over-the-counter (OTC) pain relievers to reduce fever and relieve some symptoms
- Antinausea medications
- Adequate fluid intake
- Hospitalization in severe cases
- Intravenous (IV) fluids
- Pain medication
- Nursing care
- Close monitoring
What Are Complications of EEE?
Though eastern equine encephalitis (EEE) is rare, it is very serious and can be fatal. About one-third of people infected with the virus die, usually within 2 to 10 days after onset of symptoms.
- Of those who recover, long-term physical or mental impairments are common, which can range from mild brain dysfunction to severe intellectual impairment, personality disorders, seizures, paralysis, and cranial nerve dysfunction.
- Those who have severe impairments may require long-term care and many die within a few years.
How Do You Prevent EEE?
There are no vaccines to prevent eastern equine encephalitis (EEE). To reduce the risk of infection:
- Prevent mosquito bites
- Use insect repellents containing DEET, picaridin, oil of lemon eucalyptus, 2-undecanone, para-menthane-diol, or IR3535 when outdoors
- Wear long pants and long sleeves to minimize skin exposure
- Applying permethrin to clothing (not skin)
- Drain areas of standing water (e.g., buckets, bird baths, gutters, wading pools, and pet dishes), where mosquitos frequently lay eggs
- Ensure all windows and doors have good quality screens to help keep mosquito exposure to a minimum
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https://www.cdc.gov/easternequineencephalitis/index.html