Western Equine Encephalitis Virus in South America – Level 1 – Level 1 – Practice Usual Precautions – Travel Health Notices | Travelers’ Health

Western equine encephalitis virus (WEEV) is a virus most commonly spread to people through the bite of an infected mosquito. People most at risk for infection are those who are outdoors when mosquitoes are active.

Most people infected with WEEV do not feel sick or develop a mild febrile (fever) illness. However, the virus can cause some people to develop severe neurologic disease such as meningoencephalitis (inflammation of the brain and surrounding membranes) and myelitis (inflammation of the spinal cord). Symptoms of severe illness may include high fever, headache, neck stiffness, photophobia (sensitivity to light), confusion, somnolence (drowsiness), coma, or seizures.

There are no vaccines to prevent WEEV infection. The best way to prevent infection is to protect yourself from mosquito bites.