The Chester County Health Department has made it a little safer for residents in one southern Chester County Township to go out at night.
On Friday, the department mobilized two trucks with flashing yellow lights to drive slowly through Penn and kill mosquitoes – the carriers of West Nile Virus.
Health department scientist Seth Lisinski said the trucks were to dispense an insecticide called Permanone RTU containing permethrin in an area bounded on the north by Baltimore Pike and on the two sides by routes 796 and 896. Several specific areas included in the spraying were Jenner’s Pond, Luther House, the trailer park and the rear yard of Jennersville Regional Hospital.
The spraying was to have taken place between 7:45 and 10:30 p.m. Lisinski, who was scheduled to drive one of the trucks, said the insecticide would be dispensed at the rate of an ounce-and-a-half per acre. He added that the substance is not dangerous to humans or pets but provides quick control of mosquito populations.
The health department is responding to recent test samples that show mosquitoes infected with the virus have been found all over Chester County. In Penn Township, six mosquito samples have shown to contain the virus.
On Aug. 28, the health department announced that a 59-year-old male from West Nottingham Township was hospitalized for West Nile Virus and since recovered. As of that date, 98 mosquito samples in Chester County tested positive for West Nile as compared with 29 for the entire year in 2011.
Lisinski said the presence of the virus in not unique to Penn Township or any of the other areas sprayed. “It’s all over,” he said.
According to the health department, certain mosquito species carry the West Nile Virus which, when transmitted to people, can cause West Nile encephalitis, an infection that can result in an inflammation of the brain.
According to the “Everyday Health” website, West Nile virus is a mosquito-spread infection that usually causes either no symptoms or mild symptoms of headache, fever, body aches, and sometimes a rash and swollen lymph nodes. In rare cases it can lead to inflammation of the brain (encephalitis) or the tissues surrounding it and the spinal cord (meningitis).
When West Nile virus affects the brain, symptoms may include headache, high fever, stiff neck, reduced attention to surroundings, disorientation, tremors, convulsions, muscle weakness or paralysis, and coma.
The health department recommends eliminating mosquito-breeding areas, which usually are defined as places that hold standing water outside. Among those places that water can accumulate and breed mosquitoes are old tires, recycling containers, gutters, wading pools, birdbaths and swimming pools.
They suggest making sure screens are tight, wearing long-sleeved clothing at night, staying inside during sawn and dusk and using insect repellent.