Concord, NH – The New Hampshire Department of Health and Human Services (DHHS) is announcing that a male from Hillsborough County tested positive for the Jamestown Canyon virus (JCV) and the Powassan virus, the first time either of these vector-borne diseases has been identified in the State. JCV is transmitted by infected mosquitoes and Powassan is transmitted by infected ticks.
“While this is our first announcement of Jamestown Canyon virus and Powassan virus in New Hampshire,” said Dr. José Montero, Director of Public Health at DHHS, “these have been in the U.S. for a while and Powassan was found in Maine and Vermont previously so this is not entirely unexpected. There are many mosquito- and tick-borne illnesses and unfortunately we are probably going to continue to see cases of them, which makes prevention steps all the more important. The same precautions we now take for Lyme and West Nile and EEE are effective against these viruses as well. So, as people enjoy New Hampshire we are urging them to use an effective repellent and do regular tick checks.”
Because these viruses are very rare, there is not a lot known about the illness they cause, where they are located in the environment, and how many people may have already been infected. JCV is a mosquito-borne pathogen that circulates widely in North America primarily between deer and a variety of mosquito species, but it can also infect humans. Reports in humans thus far of JCV are unusual and have been confined to the Midwestern and northeastern states. Most reported illnesses caused by Jamestown Canyon virus have been mild, but moderate-to-severe central nervous system involvement has been reported.
Powassan virus infection is caused by an arbovirus, which is similar to the mosquito-borne West Nile virus, but it is transmitted to people by infected ticks. Fewer than 60 cases of the disease have been detected in the United States and Canada since its discovery in 1958. In New Hampshire, Ixodes scapularis, or the blacklegged tick or more commonly deer tick, is capable of transmitting the virus to people. A tick needs to be attached to a person for a sufficient amount of time before it can cause disease. The time interval for Powassan virus is not known, but it is likely shorter than the time needed for Lyme disease (24–48 hours). Some people who are infected may experience mild illness or no symptoms. Powassan virus can also infect the central nervous system and cause brain inflammation.
Residents and visitors to New Hampshire should protect themselves and their family members by using an effective mosquito repellant that contains 30% DEET, wearing long sleeves and pants at dawn and dusk when mosquitoes are most active, and removing standing water from around your house so mosquitoes do not have a place to breed. Repellents with picaridin, IR3535 and some oil of lemon eucalyptus and para-menthane-diol products also provide protection.
Anyone with questions about vectorborne illnesses can call the DHHS information line at 1-866-273-6453 between 8:00 AM to 4:30 PM, Monday through Friday.