Schuylkill County's heaviest season in recent years for West Nile virus prevalence among mosquitoes should be wrapping up soon, with one human case being found to date.
Thirty-five positive cases of the bloodborne virus have been found in mosquitoes in Schuylkill this year, said Kyle Schutt, invasive species program coordinator with the Schuylkill County Conservation District.
That is the second highest total in the county since the testing program began in 2018, and that high number is likely due in part to the rainy June we had locally, which created more standing water and ideal conditions for mosquito eggs to hatch, Schutt said.
When fall weather arrives and temperatures consistently fall below 50 degrees, mosquitoes will become less active, and most will die once a hard freeze arrives.
The fewer mosquitoes there are, the less chance for humans to catch West Nile virus from the bites of the insects that are infected, Pennsylvania Department of Health officials said.
West Nile virus is the leading cause of mosquito-borne disease in the contiguous United States, according to the U.S. Centers for Disease Control and Prevention. Each year more than 1,300 people develop severe illness from the virus that affects their central nervous system, and more than 130 people die, the CDC said.
So far there have been 40 cases of the virus among humans in Pennsylvania this year, the health department said. That includes the single case in Schuylkill, which was found in July. Due to patient confidentiality, the department does not disclose where in the county the case was reported
The time for the public to help prevent a thriving mosquito population next year is now, since many mosquito species lay overwintering eggs in standing water, Schutt said. Those eggs hatch the following spring, ensuring their cycle continues.
Eliminating standing water and mosquito breed habitats is key, so the public is urged to turn over plastic wading pools and wheelbarrows when not in use, dispose of tin cans, plastic containers, ceramic pots or similar water-holding containers that have collected on your property, and to not let water stagnate in birdbaths.
The public should also aerate ornamental pools or stock them with fish and clean and chlorinate swimming pools not in use, as mosquitoes may even breed in the water that collects on pool covers.
Stagnant water in unused tires is an excellent habitat for mosquitoes to thrive, so old tires should be discarded, and buckets, tarps, downspouts and rain gutters should be cleaned regularly as well.
Even clearing small objects can make a difference. Standing water in something as little as a bottle cap can provide enough space for a mosquito egg raft, which can produce as many as 300 mosquitoes, according to the health department.
Schutt travels the county testing mosquito larvae for the virus and trapping adult mosquitoes to test them as well. The Mosquito-Borne Disease Program is funded through a state Department of Environmental Protection Grant. Most years Schutt finds about 20 or so cases among mosquitoes.
When high populations of adult mosquitoes capable of transmitting West Nile virus are detected in an area, he uses a truck-mounted ultra-low volume mosquito spray to knock down and control them.
Schutt also uses a backpack sprayer to treat areas where mosquitoes are breeding, such as wooded lots, after he gets permission from property owners.
"We want to break up their life cycle before they bite anybody," he said.