NH DHHS Identifies First Jamestown Canyon Virus and Powassan Virus Cases in NH

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 vector borne illnesses can call the DHHS

information line at 1-866-273-6453 between 8 AM to 4:30 PM, Monday through