Symptoms, Diagnosis, & Treatment


  • 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.
  • To learn more about testing, visit our Healthcare Providers page.


  • No vaccine or specific medicines are available for Jamestown Canyon virus infection.
  • Treat the symptoms:
    • Get plenty of rest
    • Drink fluids to prevent dehydration
    • Take over-the-counter pain relievers to reduce fever
  • In severe cases, patients may need to be hospitalized to receive supportive treatment, such as intravenous fluids, pain medication, and nursing care.
  • If you think you or a family member might be infected with Jamestown Canyon virus, talk with your healthcare provider.
  • To learn more about treatment, visit our Healthcare Providers page.