What’s Jamestown Canyon virus? Mosquito-borne illness in Maine

We’re proper in the midst of mosquito season, when humid situations enhance the chance of mosquito-borne illnesses being unfold to people by the bugs’ itchy bites.

This week in Maine, officers warned residents within the city of Orono that mosquitoes are within the space carrying the Jamestown Canyon viruswhich was transmitted from a mosquito to a human for the primary time in Maine in 2017, in keeping with the state’s Division of Well being and Human Companies. That is the earliest within the 12 months assessments for the virus in mosquitoes have ever come again constructive, the Maine Heart for Illness Management instructed USA TODAY.

“That is perking our ears up and making us positively look ahead to maybe a extra energetic mosquito season this 12 months,” mentioned Megan Porter, a public well being educator with the Maine CDC.

The virus, which scientists contemplate an rising public well being menace to people, could be very hardly ever transmitted to folks, however when it’s, it could possibly result in extreme neurological illnesses like meningitis and even trigger dying, in keeping with Maine well being officers.

“Extreme signs can progress very quickly, and folks can get very sick,” Porter mentioned,

West Nile virus and dengue virus are way more widespread, and the mosquitoes that carry them usually tend to transmit them to people, specialists say. Medical doctors and scientists are additionally maintaining a watch out this summer season for St. Louis encephalitis, a mosquito-borne illness that may trigger mind irritation in extreme instances.

Extra folks will come down with these sicknesses as we see extra sizzling and humid days the remainder of this summer season throughout a lot of the nation, mentioned Shannan Rossi, a biology and immunology professor on the College of Texas Medical Department in Galveston.

“Because the summer season continues, you are going to see increasingly of those native instances, and that is anticipated. We see this each single 12 months,” Rossi mentioned.

Here is what to know concerning the mosquito outlook for the subsequent couple of months, in keeping with specialists.

Jamestown Canyon virus in Maine mosquitoes

Well being officers in Maine mentioned mosquito assessments just lately taken close to the city of Orono in Penobscot County have been the state’s first constructive check end result of the 12 months for the virus.

There have been no instances of the virus in people this 12 months, Porter mentioned, and the final human case was in 2021.

The virus happens naturally in mosquitoes within the northern US states and Canada’s southern provinces, Rossi mentioned. In Maine, mosquitoes known as “snowmelt mosquitoes” − named for the primary to collect round melted snow every spring − contribute essentially the most to the virus, Porter mentioned. General, a number of species of mosquitoes carry the virus, however the variety of people contaminated from their bites is “extremely low,” Rossi mentioned.

In New York State, researchers discovered an infection charges of Jamestown Canyon virus in mosquitoes have been “considerably better” in 2012 to 2022 in contrast with 2001 to 2011.

Instances of the virus in people “isn’t one thing we hear about lots,” Rossi mentioned. “Jamestown Canyon virus is nebulous in that we regularly see it being picked up in mosquito testing should you’re searching for it.”

Folks contaminated with the virus might not present signs. Those that do might expertise vomiting, neck stiffness, lack of coordination and, in extreme instances, mind swelling and meningitis, in keeping with Maine Division of Well being and Human Companies.

In 2018, a 56-year-old man experiencing continual encephalitis brought on by the virus died, in keeping with the Maine CDC.

Testing after the person’s dying “revealed intensive neuropathologic abnormalities” in his spinal twine fluid, Harvard College researchers mentioned in a report revealed in 2021.

In 2023, there have been no instances of transmission of Jamestown Canyon virus from mosquitoes to people after three batches of mosquito testing within the state got here again constructive for the virus, the Maine well being and human companies division mentioned in a information launch.

“Though you possibly can proceed to see it in mosquitoes, that does not essentially imply it poses an enormous threat to folks,” Rossi mentioned. “However it’s nonetheless alarming, since you see one thing that is transmissible by mosquitoes and it might be in your yard.”

Nationally, there are additionally no reported instances of St. Louis encephalitis in people this 12 months, in keeping with the CDC.

West Nile Virus is widespread, Dengue may unfold extra

After first spreading to the USA in 1999West Nile Virus is now present in mosquitoes in all 48 contiguous states, in keeping with Rossi.

To this point in 2024, there have been 15 instances of mosquitoes transmitting the virus to people throughout 11 states, in keeping with the federal Facilities for Illness Management and Prevention. The 15 instances are evenly unfold throughout Texas, Mississippi, Arkansas, Tennessee, North Dakota, Nebraska, Kansas, Arizona, Michigan and Maryland, the CDC says.

As a result of this summer season is forecast to be hotter and extra humid than common, Rossi mentioned, that would result in extra instances of West Nile virus.

“What I am involved about is that we’re having hotter and longer summers than now we have historically, and what meaning is the mosquito season additionally lasts longer than it did,” mentioned Rossi, 43.

Instances of dengue fever have spiked to 1,700 in Puerto Rico this 12 months, triggering officers on the island to declare a well being emergency. The rise comes because the CDC warned nations within the Americas noticed twice as many instances in the course of the first half of 2024 in contrast with all instances from final 12 months: 9.7 million instances versus 4.6 million.

South Florida has traditionally been a sizzling spot for dengue fever in the USA, with 9 instances domestically acquired in 2024, in keeping with the CDC’s tracker. No different instances of domestically acquired dengue fever have been reported within the US exterior Florida, whereas the US Virgin Islands have reported 15 instances, the CDC says.

Instances of dengue fever in different US states have been caught overseas, in keeping with the CDC, together with a spate of dozens of reported instances in New York, Massachusetts, California and Illinois.

Nonetheless, Rossi mentioned, docs are maintaining a watch out for domestically acquired instances of the dengue virus spreading farther north of Florida.

“Because the situations get hotter and warmer, it makes it simpler for the mosquitoes to maneuver into areas the place they have not been earlier than, and now now we have to fret about locations changing into probably transmissible for dengue,” she mentioned, referring to Georgia and the Carolinas, the place 40 travel-related instances of confirmed dengue fever have already been reported, in keeping with the CDC.

How can I forestall West Nile, dengue, Jamestown Canyon virus?

The mosquitoes that carry West Nile virus chew round daybreak and nightfall, Rossi mentioned, so staying indoors throughout these instances is essential to avoiding transmission.

Mosquitoes that carry dengue usually tend to collect close to standing water nearer to folks’s houses, like in a moist yard, Rossi mentioned. Preserving home windows closed if potential is an effective protecting measure to keep away from contact with mosquitoes, she mentioned.

Aside from that, insect repellant and correct clothes can go a good distance towards saving you from bites, together with presumably virus-transmitting ones, together with the Jamestown Canyon virus.

“It is laborious to say this in 95-degree climate,” Rossi mentioned, “however put on longer sleeves.”