Jamestown Canyon Virus Statistics

Cases of Jamestown Canyon virus occur throughout the United States but are only reported sporadically. The Centers for Disease Control and Prevention (CDC) began reporting for JCV in 2004 and has since received a few reports of JCV cases each year. Under-diagnosis and under-reporting of disease are likely as diagnostic testing for JCV is not widely available. Increasing numbers of cases in recent years may be due to increased awareness and testing.

Much remains unknown about the clinical spectrum of Jamestown Canyon virus disease, but the typical presentation includes fever, and in more severe cases, meningitis or encephalitis. Human disease cases occur during warmer months when mosquitoes are active, most commonly between May and September. The virus is likely widespread throughout Minnesota.

In 2024, four cases of Jamestown Canyon virus disease were reported in Minnesota. All cases reported exposures in north-central Minnesota, and two of the patients reported neuroinvasive illness like meningitis or encephalitis. 

• 3 (75%) of the reported cases were male
• Cases ranged in age from 20 to 83 years, with a median age of 61 years
• 2 (50%) cases were hospitalized
• All four cases became ill in the summer months (June, July, or August)

Maps and Graphs

• Reported Cases of Jamestown Canyon virus disease in Minnesota by Year, 2013-2024 (PDF)
  Graph showing the number of reported cases of Jamestown Canyon virus disease in Minnesota by year.
• Reported Cases of Jamestown Canyon Virus Disease by County of Residence, Minnesota, 2013-2024 (PDF) 
  A map of the average annual incidence per 100,000 population of reported cases of Jamestown Canyon virus disease by county of residence.

Annual Summaries

• Endemic Mosquitoborne & Tickborne Arboviral Diseases: Annual Summary of Reportable Diseases
  Historical data on mosquitoborne viruses from the Minnesota Department of Health Disease Control Newsletter Annual Summary of Communicable Diseases.