High Seroprevalence of Jamestown Canyon Virus among Deer and Humans, Nova Scotia, Canada

Using residual serum samples from Nova Scotia, Canada, we found that 87.8% of tested deer and an estimated 20.6% of the human population were infected with Jamestown Canyon virus.Human seropositivity reached 48.2% in 1 region.This virus may be an underrecognized cause of disease in Nova Scotia. J amestown Canyon virus (JCV), a mosquitoborne arbo-virus, belongs to the California serogroup (CSG) in the Bunyaviridae family.The primary reservoir host for JCV is considered to be the white-tailed deer, although JCV antibodies have been observed in other mammals, including horses, sheep, and cattle (1).JCV-associated illness among humans is rarely documented; rates of ≤0.01 cases/100,000 population have been reported in the United States (2,3).Infections can be asymptomatic or associated with a variety of manifestations, including fever, headache, myalgia, weakness, and seizure (4-6).Evidence of JCV in Atlantic Canada was reported in 1981 when 6 of 289 hunter-killed moose during the 1977-1978 hunting season in Nova Scotia (NS) were seropositive (7).There is no surveillance for JCV in NS, nor is it on the list of diseases notifiable to Provincial Public Health as defined in the NS Health Protection Act (8), but it could be reported as an unusual disease occurance or a disease occuring more frequently than expected.We undertook this study to determine the seroprevalence of JCV in humans and white-tailed deer in this province.