Westmoreland Conservation District is urging residents to take precautions against tick and mosquito bites as samples of the pests collected in the county have tested positive for Lyme disease, West Nile virus and a less familiar new threat — Jamestown Canyon virus.
Chrissy Edwards-McCune, West Nile Virus coordinator for the conservation district, reported Tuesday that West Nile virus has been found among mosquitoes trapped at four sampling sites — in Youngwood, West Newton, Rostraver and New Kensington.
Mosquitoes trapped at another site in New Florence have tested positive for Jamestown Canyon virus, another disease the insects can spread to humans through their bite. That same virus was found last summer in mosquito samples from the New Florence area.
Jamestown Canyon virus first cropped up in Colorado in 1961. Testing for the disease began in Pennsylvania in 2022.
It has been known to cause severe conditions including infection of the brain and spinal cord.
“Additional trapping has been conducted at all of the mosquito virus-positive sites to see if viruses were more widespread,” Edwards-McCune said.
She said residents near the sites and the municipalities where they live have been advised of the positive tests.
Local areas of standing water have been treated with larvicide to help prevent mosquitoes developing into adults.
The Pennsylvania Department of Environmental Protection reported that 24 mosquito samples in Allegheny County and one in Butler County have tested positive for West Nile virus.
Jamestown Canyon virus has not been detected in either county.
As a result of the Allegheny virus results, that county’s health department said it planned to treat areas with mosquito spray in 11 Pittsburgh neighborhoods and in Edgewood, Wilkinsburg and Mt. Oliver Borough.
According to state officials, no human cases of West Nile virus had been detected in any Pennsylvania county this year.
Mid-August to mid-September has been a peak time for human infections with the virus, Edwards-McCune said.
To limit potential exposure to mosquito bites, she recommended avoiding time outdoors at dusk and dawn, wearing long pants and long-sleeved shirts and using mosquito repellent.
She said she will continue trapping mosquito samples until Oct. 3.
Most people who are infected with West Nile virus don’t feel sick. One in five infected people will develop a fever and other symptoms, which can include headache, body aches, joint pains, vomiting, diarrhea or a rash.
Mosquitoes aren’t the only concern for the potential spread of disease.
Ticks in Westmoreland County have been testing positive for Lyme disease and anaplasmosis, Edwards-McCune said. Both are bacterial infections.
Based on the density of infected deer tick nymphs (the arachnid’s immature state) collected from 2020 through 2024, state officials indicate there is a high risk of people encountering an infected tick in all counties throughout Western Pennsylvania and those in the northcentral part of the state.
According to the Centers for Disease Control and Prevention, Lyme disease symptoms include fever, headache, fatigue and a characteristic “bullseye” skin rash. If left untreated with antibiotics, the infection can spread to joints, the heart and the nervous system.
Symptoms within one to five days of an anaplasmosis infection may include fever, headache, chills, muscle aches, nausea and diarrhea. Left untreated, it can lead to more severe illness including respiratory failure and organ failure.
Despite its name, Edwards-McCune said, the deer tick also can be spread by such smaller animals as rabbits and mice.
In addition to wooded areas or fields with high grasses, she said, ticks “can be in any of our yards.”
She said she collects ticks by dragging a large piece of white felt through their habitat, such as leaf litter. The ticks are picked off the fabric and sent to a lab to be tested for diseases.
According to Edwards-McCune, ticks can be active at any time of the year, as long as the temperature is above freezing.
“This past winter we had some freezing temperatures, but snow on the ground created insulation for them,” she said.
Nymphs are most active in the spring, while adult ticks are more common when fall arrives.
Adult deer ticks are about the size of a sesame seed. Officials recommend wearing light-colored clothes when outdoors — with shirts tucked into pants and pant legs tucked into socks — to make it easier to spot any ticks that have hitched a ride.
Tick repellents are available that can be applied to the skin or clothing.
After being outside around vegetation, it’s advisable to check body areas for ticks and to take a shower. Any ticks should be removed as soon as possible to limit the chance of infection.
Jeff Himler is a TribLive reporter covering Greater Latrobe, Ligonier Valley, Mt. Pleasant Area and Derry Area school districts and their communities. He also reports on transportation issues. A journalist for more than three decades, he enjoys delving into local history. He can be reached at jhimler@triblive.com.
