DHHS Identifies Second Jamestown Canyon Virus Case Of The 2020 Arboviral Season In New Hampshire

Concord, NH - The New Hampshire Department of Health and Human Services (DHHS), Division of Public Health Services (DPHS) is announcing that an adult from Bow, NH, tested positive for Jamestown Canyon virus (JCV). The person was not hospitalized and is doing well, but experienced fever and mild neurological symptoms. This is the second detection of JCV in the State this year. JCV is transmitted by the bite of an infected mosquito. There are no vaccines to prevent JCV and treatment consists of supportive care.

The arboviral risk level for Bow will be increased to high. The arboviral risk level indicates the risk of transmission of these infections to people from mosquitoes. The surrounding towns of Goffstown, Dunbarton, Hopkinton, and Allenstown will increase to moderate. The risk level for the surrounding towns of Hooksett, Pembroke and Concord will remain moderate.

"Jamestown Canyon Virus is one of three different infections that can be transmitted through the bite of a mosquito in New Hampshire," said Dr. Benjamin Chan, NH State Epidemiologist. "This is the second infection identified in NH this year, and the risk for mosquito-transmitted infections will only increase through the summer and fall until there is a mosquito-killing hard frost. New Hampshire residents and visitors need to continue to take steps to protect themselves from mosquito bites."

Jamestown Canyon virus is a mosquito-borne pathogen that circulates widely in North America primarily between deer and mosquitoes but can also infect humans. Reports in humans have been increasing over the last several years as recognition and testing for this virus has increased. This is New Hampshire's eleventh 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 addition to JCV, risk for infection in NH by Eastern Equine Encephalitis virus (EEEV) and West Nile Virus (WNV) will continue to increase through the summer and fall until mosquitoes are no longer biting. Residents of and visitors to New Hampshire should continue to protect themselves and their family members. Prevention guidelines are included below.

People can be infected and not develop any symptoms, or only develop very mild symptoms for all of the mosquito-borne diseases present in New Hampshire. 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.
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 www.cdc.gov.