Jamestown Canyon virus

Person applying insect repellant onto their arm.

Jamestown Canyon virus is spread to people by infected mosquitoes. The virus is found throughout much of the United States, but most cases are reported from the upper Midwest. Cases occur from late spring through mid-fall. Fever, headache, and fatigue are common symptoms with Jamestown Canyon virus disease. Jamestown Canyon virus can cause severe disease, including encephalitis (inflammation of the brain). There are no vaccines to prevent or medicines to treat Jamestown Canyon virus infection. Reduce your risk of infection by preventing mosquito bites.