St. Louis Encephalitis Symptoms
For basic information on St. Louis encephalitis symptoms, please visit the fact sheet.
Less than 1% of St. Louis encephalitis viral infections are clinically apparent and the vast majority of infections remain undiagnosed. Illness ranges in severity from a simple febrile headache to meningoencephalitis, with an overall case-fatality ratio of 5 to 15%. The disease is generally milder in children than in adults, but in those children who do have disease, there is a high rate of encephalitis (inflammation of the brain). The elderly are at highest risk for severe disease and death.
Page last modified: June 11, 2007
Content Source:
Division of Vector Borne Infectious Diseases
National Center for Zoonotic, Vector-Borne, and Enteric Diseases
Content Source:
Division of Vector Borne Infectious Diseases
National Center for Zoonotic, Vector-Borne, and Enteric Diseases