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Disease Carriers

Viruses: LaCrosse Virus

La Crosse Virus is an arbovirus (a virus transmitted by insects); it is one of the most important mosquito-borne viruses in the United States. It is most common in the hardwood forest areas of the upper midwestern United States and in the Appalachian region (West Virginia, North Carolina, Tennessee, Virginia). Recently, most cases were from West Virginia.

Encephalitis caused by this virus is most common in children and young adults (those under the age of 19). Patients may have all or some of the following symptoms: fever, vomiting, stiff neck, headache, lethargy, seizure, and even coma. There is no specific therapy, but most patients recover (death is less than 1%).

As mentioned, this virus is transmitted by mosquitoes (Aedes species). These are "tree hole" mosquitoes that lay their eggs in water-holding containers like old tires and tree holes. The primary reservoirs of the virus are small forest mammals (like the eastern grey squirrel and chipmunks).

Two views of La Crosse virus as seen by transmission electron microscopy and the negative-stain technique
Two views of La Crosse virus as seen by transmission electron microscopy and the negative-stain technique.

Learn more about arboviral infections.