Saint Louis Encephalitis

Saint Louis Encephalitis Virus (SLEV) is spread to people by the bite of an infected mosquito. Most cases of SLEV disease have occurred in eastern and central states. Most of the people infected with SLEV have no apparent illness. However, for those that do fall ill from SLEV will display initial symptoms that will include fever, headache, nausea, vomiting, and tiredness.

Severe neuroinvasive disease (often involving encephalitis, an inflammation of the brain) occurs more commonly in older adults. In rare cases, long-term disability or death can result. There are no vaccines to prevent nor any medications to treat SLEV. Care is based on symptoms.

You can reduce your risk of being infected with SLEV by using insect repellent, wearing long-sleeved shirts and long pants, and staying indoors while mosquitoes are most active. If you think you or a family member may have SLEV neuroinvasive disease, it is important to consult your healthcare provider for proper diagnosis.