Jamestown Canyon Virus

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What is Jamestown Canyon virus?

Jamestown Canyon virus is a potentially serious illness spread to people by infected mosquitoes. It was first identified in 1961 in mosquitoes from Jamestown Canyon, Colorado, and is now found throughout much of the United States. Most cases are reported from the upper Midwest.

What are the symptoms of Jamestown Canyon virus?

If symptoms develop, they usually appear a few days to 14 days after the bite of an infected mosquito. Initial symptoms can include:

  • Fever
  • Fatigue
  • Headache
  • Cough
  • Sore throat
  • 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
  • Seizures.

What is the treatment for Jamestown Canyon virus?

There is no treatment to cure Jamestown Canyon virus disease. About half of patients reported with Jamestown Canyon virus disease are hospitalized for supportive treatment.

What should I do if I think I have Jamestown Canyon virus?

See your healthcare provider if you develop the symptoms described above. Your healthcare provider can order tests to look for Jamestown Canyon virus infection. You can also treat the symptoms of the infections by:

  • Getting plenty of rest.
  • Drinking fluids to prevent dehydration.
  • Taking over-the-counter pain relievers to reduce fever.

How can Jamestown Canyon virus be prevented?

The best way to avoid Jamestown Canyon virus infection is to prevent mosquito bites:

  • Use insect repellent. The Centers for Disease Control and Prevention (CDC) recommends the use of insect repellents containing active ingredients registered with the U.S. Environmental Protection Agency (EPA). Always follow manufacturer's directions carefully. Be careful using repellant on the hands of children because repellents may irritate the eyes and mouth.
  • Wear protective clothing such as long-sleeved shirts and pants.
  • Limit outdoor activity from dusk to dawn when mosquitoes are most active.
  • Avoid areas where mosquitoes may be present (i.e. shaded and wooded areas).
  • Maintain window and door screens to keep mosquitoes out of buildings.
  • Get rid of mosquito breeding sites by emptying standing water that collects in birdbaths, boats, buckets, tires, unused pools, roof gutters and other containers.



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