A wildlife disease primer

Certain species of mosquitoes carry the West Nile virus. (Environment Canada)

Marking the first Pennsylvania case of 2020, state officials announced Thursday that they believe they’ve identified someone suffering with West Nile Virus in Potter County.

That’s nearly four hours and 200 miles away from Lancaster County, but state officials pointed out that mosquitoes carrying the illness have been found locally, too.

In fact, a total of 32 insects carrying West Nile were found in Lancaster County during a 2019 mosquito sampling, according to Neil Shader, a state Department of Environmental Protection spokesman.

People can get the virus when they are bitten by infected mosquitoes, according to the U.S. Centers for Disease Control and Prevention.

Only about one-in-five people infected with the virus will develop symptoms, and only one-in-150 will become seriously ill, according to the CDC.

Severe symptoms include: high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis.

“Recovery from severe illness might take several weeks or months. Some effects to the central nervous system might be permanent,” CDC officials said. “About one out of 10 people who develop severe illness affecting the central nervous system die.”

Both state and federal officials urged Pennsylvanians to wear bug repellent when outside and to see a doctor if experiencing symptoms.

According to the Thursday announcement, samples from the Potter County case will be sent to the CDC, where health officials will conduct tests to confirm whether the virus is, in fact, present.

Locally, mosquito activity is most common August through September, but that can vary depending on weather conditions, Shader said. And state officials said the insects are most active at dawn and dusk.

Biologists with the DEP regularly conduct mosquito surveillance, and while Shader couldn't identify risky locations in Lancaster County, he said locals should avoid areas with standing water, where mosquitoes often accumulate and breed.

“Places like old industrial sites ... can be heavy with mosquitoes,” he said.


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