Jamestown Canyon Virus is transmitted to people by infected mosquitos. Mosquitos become infected when they feed on infected deer. The virus is found throughout much of the United States, but Minnesota and Wisconsin have reported more than half of the cases. Most infections occur between April and September.
The time from mosquito bite to development of symptoms ranges from a few days to 2 weeks. Initial symptoms can include fever, fatigue, and headache. Jamestown Canyon Virus can cause encephalitis. Approximately half of infected people are hospitalized but deaths are rare. Approximately 17 neuroinvasive cases are reported each year.
Diagnosis is usually made by testing for Jamestown Canyon virus-specific IgM antibody M followed by a confirmatory plaque reduction neutralization test (PRNT).
References
Patriquin G, Drebot M, Cole Teri, et al. High seroprevalence of Jamestown Canyon virus among deer and humans, Nova Scotia, Canada. Emerg Infect Dis 2018;24:118‒121.
Pastula DM, Hoang Johnson DK, White JL, Dupuis AP, Fischer M, Staples JE. Jamestown Canyon virus disease in the United States — 2000–2013. Am J Trop Med Hyg 2015;93:384–389.