West Nile Virus has now been found in two Main Line communities this summer, with the latest detection just across the township line from Radnor in the Wynnewood section of Lower Merion.
Montgomery County health officials confirmed that a mosquito sample collected Thursday, Aug. 13 in Wynnewood tested positive for the virus, Mainline Media News reported. The finding comes roughly three weeks after the Delaware County Health Department reported a positive mosquito sample in Radnor Township on July 24, according to the department's environmental health alerts page. A separate Radnor Township notice dated July 29 identified a positive trap at Encke Park.
No human cases have been reported in Eastern Pennsylvania this year.
Delaware County detections
The Wynnewood detection sits adjacent to Radnor's eastern border. And the virus has been spreading across Delaware County all summer. The health department has logged nine positive mosquito samples since June 25, including detections in both Haverford Township (July 10) and Radnor Township (July 24).
Other Delaware County communities with positive samples include Collingdale, Swarthmore, Brookhaven, Yeadon, Norwood and Lansdowne.
Lower Merion officials said in a press release that the area's rainy, hot and humid summer created ideal conditions for mosquitoes to thrive, and urged residents to take precautions against bites.
What officials are saying
Montgomery County's Office of Public Health said additional analysis is underway to determine mitigation measures for the Wynnewood area. Treatment decisions will be based on surveillance data and guidance from mosquito control experts, according to Patch.
On the Delaware County side, the health department may initiate adult mosquito spraying if surveillance shows a threat to human health. Any spray events are planned at least 48 hours in advance. The county does not conduct nuisance spraying or take public requests for it.
Delaware County Health Department Director Lora Siegmann Werner urged residents in June, when the county's first positive sample was identified in Collingdale, to take weekly action. "Once a week, empty and scrub, turn over, cover, or throw out any items that hold water like buckets, planters, toys, or trash containers," Werner said in the department's June 25 press release. "This really makes a difference!"
How to protect yourself
Health officials in both counties recommend:
- Remove or drain standing water from gutters, tires, buckets, planters and containers
- Keep window and door screens in good condition
- Avoid outdoor activities from dusk to dawn, when mosquitoes are most active
- Wear long sleeves, pants and socks outdoors in the evening
- Use EPA-registered mosquito repellent
About 1 in 5 people infected with West Nile develop symptoms including fever, headache, body aches and rash. About 1 in 150 develop severe illness affecting the central nervous system.
Mosquito season in Delaware County typically runs through October.
Residents with questions can contact the Delaware County Health Department's Wellness Line at (484) 276-2100 or the Montgomery County Office of Public Health at 610-278-5117.
