04/08/25 Public Health Education Topic: La Crosse Encephalitis

Per CDC:

Key Points

La Crosse virus is spread to people by the bite of an infected mosquito.
Most people infected with the virus do not have symptoms.
Some people may develop severe disease, most commonly children under 16 years of age.
You can reduce your risk of infection by preventing mosquito bites.

Overview:

Most cases occur in the upper Midwestern, mid-Atlantic, and southeastern states.
Most people infected with the virus do not have symptoms.
Initial symptoms can include fever, headache, nausea, vomiting, and fatigue. Some people may develop severe disease, including encephalitis (inflammation of the brain). Severe disease occurs most often in children under 16 years of age.
There are no vaccines to prevent or medicines to treat La Crosse. You can reduce your risk of infection by preventing mosquito bites.