Date: August 06, 2021


Public Information Office
(603) 271-9389

DHHS Identifies First Person Infected With The Jamestown Canyon Virus In New Hampshire During The 2021 Arboviral Season

Concord, NH - The New Hampshire Department of Health and Human Services (DHHS), Division of Public Health Services (DPHS) is announcing an adult from Dublin, NH tested positive for Jamestown Canyon virus (JCV), a viral infection transmitted through the bite of an infected mosquito. This is the first detection of JCV in a person in the State this season.

The arboviral risk level for cities and towns indicates the risk of transmission of mosquito-borne diseases to people. The arboviral risk level for Dublin will be increased to high as a result of this identified infection. The risk level for surrounding towns of Harrisville, Peterborough, Jaffrey, and Marlborough will increase to moderate.

The person infected with JCV was hospitalized with worsening neurological symptoms and ultimately died; JCV infection was identified as a contributing cause to their death. We offer our sympathies to the family and friends.

“Jamestown Canyon Virus and the other mosquito-borne infections can cause serious illness,” said Dr. Benjamin Chan, NH State Epidemiologist. “As summer progresses into fall, the risk from mosquito-transmitted infections is expected to increase. So residents and visitors to New Hampshire should take precautions to avoid mosquito bites, especially as people are encouraged to spend more time outdoors during the COVID-19 pandemic.”

JCV is a mosquito-borne pathogen that circulates widely in North America primarily between deer and mosquitoes but can also infect humans. In addition to JCV, Eastern Equine Encephalitis virus (EEEV) and West Nile virus (WNV) can also be spread to people through mosquitoe bites.

People can be infected and not develop any symptoms, or only develop very mild symptoms for all three mosquito-borne diseases. Early symptoms can include fever, muscle aches, headaches, and fatigue. More serious central nervous system disease, including meningitis or encephalitis can occur with these diseases. If you or someone you know is experiencing symptoms, including fever and headache, contact your local medical provider. There are no vaccines to prevent JCV and care consists of treating symptoms to keep the individual comfortable.

Reports of JCV in humans have been increasing over the last several years as recognition and testing for this virus has increased. This is New Hampshire’s fifteenth case of JCV since the first report of the disease in the State in 2013. Many illnesses caused by JCV are mild, but moderate-to-severe central nervous system involvement requiring hospitalization have been reported, including fatal infections. In NH, human cases of JCV have been recorded as early as mid-May and as late as early November.

Anyone with questions about vector-borne illnesses can call the DPHS Bureau of Infectious Disease Control at (603) 271-4496 from 8 AM to 4:30 PM, Monday through Friday. More information can also be found online at