New Florence mosquito tests positive for virus similar to West Nile

A mosquito sample taken in New Florence has tested positive for a rare disease that first cropped up in Colorado in 1961 and has been known to cause severe conditions including infection of the brain and spinal cord.

There haven’t been any reported cases of the Jamestown Canyon virus being spread to humans this year in Westmoreland or Allegheny counties, according to state records.

Since the state Department of Environmental Protection began testing for Jamestown Canyon virus in 2022, it has been found in mosquito samples in 11 Pennsylvania counties. In addition to Westmoreland County, positive samples have been found this year in Crawford and Luzerne counties. Four samples tested positive in Armstrong County last year.

So far this season, there have been no mosquitoes in Westmoreland County found to be carrying the better-known West Nile virus. Eight samples tested positive for West Nile in Allegheny County, including seven in Pittsburgh neighborhoods and one in Baldwin.

The Pennsylvania Department of Health said many people who are infected with Jamestown Canyon virus have no symptoms, but about half of the known cases have resulted in hospitalization. Related deaths have been rare.

Symptoms of the Jamestown Canyon disease can occur anywhere from a few days to two weeks after being bitten by an infected mosquito.

Symptoms can include fever, fatigue, headache, cough, sore throat or runny nose. Signs of a more severe reaction to the virus can include stiff neck, confusion, loss of coordination, difficulty speaking and seizures.

West Nile virus shares many of the same symptoms, as well as possible body aches, vomiting, diarrhea or a rash.

The Centers for Disease Control and Prevention said only about 20% of those infected with West Nile virus develop any symptoms and about 1 in 150 may develop a severe illness.

People can help protect themselves against exposure to disease-bearing mosquitoes by eliminating conditions that can create a breeding ground for the pests.

“Mosquito larvae need water to complete their life cycle, and they only take five to seven days to become adults,” said Chrissy Edwards-McCune, West Nile virus technician with the Westmoreland Conservation District. “Mosquitoes can breed in just a capful of water. You can prevent mosquitoes from breeding around your home by regularly dumping, cleaning and turning over any containers that may collect water, keeping gutters clean of debris and properly disposing of or recycling any unwanted tires.”