Jamestown Canyon Virus

Jamestown Canyon Virus

Jamestown Canyon Virus

The 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. Most cases occur from late spring through mid-fall.

Fever, headache, and fatigue are common symptoms with Jamestown Canyon virus disease. Jamestown Canyon virus can rarely cause severe disease, including infection of the brain (encephalitis) or the lining around the brain (meningitis). There are no vaccines to prevent or medicines to treat Jamestown Canyon virus infection. Reduce your risk of infection by avoiding mosquito bites.


Many people infected with Jamestown Canyon virus do not have symptoms. For people with symptoms, the time from mosquito bite to feeling sick ranges from a few days to 2 weeks.
Initial symptoms can include fever, fatigue, and headache. Some people also have respiratory symptoms such as cough, sore throat, or runny nose. Jamestown Canyon virus can cause severe disease, including infection of the brain (encephalitis) or the membranes around the brain and spinal cord (meningitis). Symptoms of encephalitis or meningitis include stiff neck, confusion, loss of coordination, difficulty speaking, or seizures. About half of patients reported with Jamestown Canyon virus disease are hospitalized. Deaths associated with Jamestown Canyon virus infection are rare.


See your healthcare provider if you develop the symptoms described above. Your healthcare provider can order tests to look for Jamestown Canyon virus infection.
More information on diagnostic testing is available on the CDC’s  “Healthcare Providers” page.


There is no medicine to treat Jamestown Canyon virus infection. Treat the symptoms as follows:

  • Get plenty of rest.
  • Drink fluids to prevent dehydration.
  • Take over-the-counter pain relievers to reduce fever.
  • Some patients with severe symptoms may need to be hospitalized.

In the News

A recent case of Jamestown Canyon Virus (JVC) in Dublin, New Hampshire was the fifteenth case of JCV since the first report of the disease in the State in 2013. Many illnesses caused by JCV are mild, but moderate-to-severe central nervous system involvement requiring hospitalization have been reported, including fatal infections. In NH, human cases of JCV have been recorded as early as mid-May and as late as early November.

The arboviral risk level for Dublin will be increased to high as a result of this identified infection. The risk level for surrounding towns of Harrisville, Peterborough, Jaffrey, and Marlborough will increase to moderate.

Residents and visitors to New Hampshire should take precautions to avoid mosquito bites, especially as people are encouraged to spend more time outdoors during the COVID-19 pandemic.

Anyone with questions about vector-borne illnesses can call the DPHS Bureau of Infectious Disease Control at (603) 271-4496 from 8 AM to 4:30 PM, Monday through Friday. More information can also be found online at www.dhhs.nh.gov and www.cdc.gov.

Additional CDC Resources

CDC’s Jamestown Canyon Virus Page


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