La Crosse Encephalitis home

La Crosse encephalitis is a viral disease spread to people by the bite of an infected mosquito. Most cases occur in the upper Midwestern, mid-Atlantic, and southeastern states. Many people infected have no apparent symptoms. Some of those who become ill develop severe neuroinvasive disease (disease that affects the nervous system). Severe disease often involves encephalitis (an inflammation of the brain) and can include seizures, coma, and paralysis. Severe disease occurs most often in children under the age of 16.