West Nile virus found in Westmoreland, Allegheny, Armstrong; mosquito spraying slated

Mosquitoes sampled in Westmoreland County have tested positive for West Nile virus — joining Allegheny County, where spraying to control the insects is set to resume.

One positive human case has been reported in neighboring Armstrong County, though the disease was not found in any mosquitoes there, according to the state Department of Environmental Protection.

In Westmoreland County, four positive results in mosquitoes were found — in Derry, Greensburg, Youngwood and Mt. Pleasant — as of Friday, according to Chrissy Edwards-McCune, West Nile virus technician for the Westmoreland Conservation District.

According to data from the state, Westmoreland ranks 22nd among 44 Pennsylvania counties where positive results have been detected so far this season among mosquitoes.

York County ranks first, with 295 positive results, while Allegheny County is seventh, with 59 positive results. Fayette and Washington counties each had three positive cases.

In Allegheny County, health officials plan to spray pesticide Zenivex E20 to control mosquitoes from 8 to 11 p.m. Wednesday in Mt. Oliver Borough and in several Pittsburgh neighborhoods: Arlington, Arlington Heights, Chartiers, Crafton Heights, Elliott, Southside Flats, Southside Slopes and Sheridan. If it rains, the spraying detail will be rescheduled for Aug. 29.

It will be the third round this summer of spraying the mosquito pesticide in Allegheny County. Officials previously applied it on Aug. 11 in Pittsburgh’s southern neighborhoods and on Thursday in the city’s eastern neighborhoods.

The treatment is not harmful to humans or pets, according to health officials.

Each week in Westmoreland County Edwards-McCune sets at least 15 traps, which typically snare between 50 and 100 mosquitoes over a 24-hour period. Resulting mosquito samples are sent to the state Department of Environmental Protection for testing to see if they are positive for infection with the West Nile virus.

“If I get a positive when I’m collecting mosquitoes, I’ll set another trap nearby,” she said.

Infected mosquitoes can transmit the disease to humans that they bite. Seven positive cases have been found so far in humans in the state this year. In addition to the case in Armstrong, others were reported in Berks, Dauphin, Lancaster, Luzerne, Philadelphia and Tioga counties.

An estimated one in five people with West Nile virus will develop mild symptoms, Edwards-McCune said. Common symptoms of the virus are typically like those of a mild flu, such as fever, headache, body aches, skin rashes and swollen lymph nodes.

More severe infections can result in meningitis and encephalitis, she said. An estimated 1 in 150 people infected with the virus develop more severe symptoms.

Edwards-McCune advised that residents can help protect themselves from infection by eliminating mosquito breeding habitat, such as stagnant water, on their property. They also may consider using mosquito repellent and wearing long sleeves and pants, especially around dusk and dawn.

Mosquito larvae need water to complete their life cycle, but just a bottle cap full of water is sufficient, with the insects developing into adults in just 5-7 days, according to Edwards-McCune.

She encouraged homeowners to prevent mosquitoes from breeding by “regularly dumping, cleaning and turning over any containers that may collect water (such as bird baths, kiddie pools and toys, tarps and trash cans), keeping gutters clean of debris and properly disposing of or recycling any unwanted tires.”