pdf Version | Information from CDC about La Crosse Encephalitis
What is La Crosse encephalitis?
La Crosse (LAC) encephalitis is a mosquito-borne virus that was discovered in La Crosse, Wisconsin in 1963. Since then, the virus has been identified in several Midwestern and Mid-Atlantic states, including western parts of Virginia.
Who gets LAC?
Most cases of LAC encephalitis occur in children under 16 years of age.
How is LAC transmitted?
LAC is transmitted to humans through the bite of an infected tree-hole mosquito. Mosquitoes are infected by biting a chipmunk or squirrel that is infected with the virus. Tree-hole mosquitoes are daytime biters and can live not only in tree holes, but also in containers that hold water for more than a week. People can not get LAC from chipmunks or squirrels.
What are the symptoms of LAC?
LAC is typically a summertime illness. Initial symptoms include fever, headache, nausea, vomiting and lethargy. Severe disease occurs most commonly in children under the age of 16 and is characterized by seizures, coma, paralysis, and a variety of neurological complications after recovery. Death from LAC encephalitis occurs in less than 1% of clinical cases.
How many human cases of LAC have been reported in Virginia?
The first human case of LAC was reported in the state in 1996. Traditionally, a few cases of LAC are reported each year in far Southwest Virginia and a total of 16 cases of LAC have been reported in Virginia. Four cases of LAC were reported in 2003.
How Can LAC be prevented?
Where can I get more information on LAC?
Call your local health department of visit one of the following sites: