A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Facebook Twitter LinkedIn Syndicate Emerging Infectious Disease journal ISSN: 1080-6059 Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.
Jamestown Canyon virus (JCV) is an underreported mosquitoborne arbovirus that can cause viral encephalitis in humans. To determine whether humans in greater Chicago, Illinois, USA, were at risk for JCV infection, we conducted surveillance on mosquito populations in suburban forest preserves with seasonal wetland habitats likely to sustain enzootic transmission. We documented the diversity and abundance of putative vector mosquito species to determine their prevalence for JCV infection. Of 11 predominantly mammalophilic mosquito taxa screened, we detected JCV in 5 species. The highest JCV prevalence was in Anopheles punctipennis , followed by Aedes stimulans group, Ae. canadensis , Ae. trivittatus , and Coquillettidia perturbans mosquitoes. Most detections were from mosquitoes collected in June and early July, and earliest detections were limited to Ae. stimulans group female mosquitoes. Our findings indicate substantial potential for human JCV exposure where urban development encroaches on natural habitats in northeastern Illinois. We urge continued surveillance for JCV.
Jamestown Canyon virus (JCV) is a member of the California serogroup of orthobunyaviruses and can cause acute febrile illness as well as neuroinvasive disease such as encephalitis or meningitis ( 1 , 2 ). The geographic distribution of apparent human disease in the United States is concentrated in the northeastern and upper Midwest regions; Minnesota and Wisconsin account for more than half of reported JCV cases ( 1 – 3 ). Although reported human infections are relatively uncommon, clinical cases likely underestimate the true intensity of transmission because most JCV infections are asymptomatic or mild, diagnostic cross-reactivity complicates confirmation, and routine testing has historically been limited ( 4 ). In addition, detections in a variety of mosquito species and mammalian hosts indicate that the virus has a wider geographic distribution than case counts alone suggest ( 2 , 5 ). Together, those observations suggest that the geographic extent of JCV transmission and rate of human exposure in the United States are likely underestimated by case-based surveillance.
Across endemic regions of the United States and Canada numerous mosquito species have been implicated as competent or regionally consequential JCV vectors ( 5 ). For example, Aedes stimulans was identified as the primary overwintering mosquito host and early season vector in northern Indiana ( 6 ), Ae. canadensis has been incriminated as the main early season mosquito vector in Connecticut ( 7 ), and Ae. provocans appears to be the key early season mosquito vector of JCV in Wisconsin, Michigan, and upper New York state ( 8 – 10 ). Therefore, region-specific knowledge of the possible contributions of vector species to virus maintenance and zoonotic amplification is essential for developing effective surveillance and vector management strategies, and for understanding risk for exposure in humans.
In Illinois, USA, a high incidence of mosquitoborne virus cases has been observed in recent decades, most of which were attributed to West Nile virus ( 11 ), and few human JCV inf…