Mosquitoes are spreading yet another disease in Maine

Maine health officials just confirmed that a relatively rare disease carried by mosquitoes has sickened two more people. No, it’s not West Nile virus. Or Eastern Equine Encephalitis.

This one is called Jamestown Canyon virus. Thanks, mosquitoes, we really needed one more reason to detest you.

A mosquito from the genus Aedes, which can carry Jamestown Canyon virus. Jeffrey Arguedas | EFE | Zuma Press | TNS

(Oh and ticks, don’t think we’ve forgotten what creeps you all are.)

JCV first popped up in Maine in mid-July when it sickened a Kennebec County man. Over the last week, the Maine Center for Disease Control and Prevention identified two more cases, according to a new report. One was in Franklin County and the other in a New Hampshire resident who presumably grew ill while in Maine.

Several mosquito species carry JCV, including those present in the state. Infected mosquitoes spread the illness to humans through a bite. The symptoms are similar to West Nile and EEE, including fever, body aches, neck stiffness, and other flu-like symptoms. Some patients also develop serious complications including brain swelling or meningitis.

Like the other two illnesses transmitted by mosquitoes, JCV is not contagious or spread from animals to humans. There is no treatment for the disease, other than supportive care such as keeping patients hydrated.

It’s hard to pin down the significance of the two new cases, said Dr. Siiri Bennett, Maine’s state epidemiologist. Doctors don’t routinely test for the illness, so she suspects there are more cases in Maine that just haven’t been identified.

“There’s so much we don’t know about this virus,” she said. “It’s alarming to know that it’s out there, that there’s another virus you need to be aware of.”

JCV was first identified in 1961 in Jamestown Canyon, Colorado. It’s since been found in mosquitoes throughout the Northeast, West and Midwest, but human cases are rare. Only 15 cases occurred in the U.S. between 2004 and 2011, according to the U.S. CDC. Another study identified 31 cases between 2000 and 2013.

Testing for JCV can take weeks to return results, so the individuals in these new cases may have contracted the disease earlier this summer. The Kennebec County man started showing symptoms as early as June.


The good news is that you can take simple steps to minimize the risk of a mosquito bite, Bennett said. That’s much easier said than done in a state where pink welts from mosquito bites are a surer sign of summer than skin tans, but I’ll run through them just for good measure:

  • Wear long sleeves and pants outside
  • Use an EPA-approved repellent on skin and clothes 
  • Take extra precautions at dusk and dawn, when mosquitoes are most active
  •  Use screens on your windows and doors
  •  Drain artificial sources of standing water 
Jackie Farwell

About Jackie Farwell

I'm the health editor for the Bangor Daily News, a Bangor native, a UMaine grad, and a weekend crossword warrior. I never get sick of writing about Maine people, geeking out over health care data, and finding new ways to help you stay well. I live in Gorham with my husband Nick and our hound dog Riley.