About St. Louis Encephalitis

Key Points

  • St. Louis encephalitis virus is spread to people by the bite of an infected mosquito.
  • Symptoms include fever, headache, nausea, vomiting, and tiredness.
  • There are no vaccines to prevent or medicines to treat St. Louis encephalitis.
  • You can reduce your risk by taking steps to avoid mosquito bites.
Culex species mosquito

Overview

St. Louis encephalitis virus is spread to people by the bite of an infected mosquito. Most people infected with St. Louis encephalitis virus do not have symptoms. Those people who do become ill may experience fever, headache, nausea, vomiting, and tiredness.

Some people may develop neuroinvasive disease, such as encephalitis (inflammation of the brain) or meningitis (inflammation of the membranes that surround the brain and spinal cord). In rare cases, long-term disability or death can occur.

There are no vaccines to prevent or medicines to treat St. Louis encephalitis. Reduce your risk of infection by preventing mosquito bites.

Print
Content Source:
National Center for Emerging and Zoonotic Infectious Diseases (NCEZID)