West Nile virus earlier, more prevalent

The vast majority of positive samples of the mosquito-borne virus are in Delaware County.

West Nile virus is being spotted earlier and in greater numbers than in previous years, especially in southeastern Pennsylvania.
(Photo: Flickr/James Jordan)

The Pennsylvania Department of Environmental Protection has identified 25 sites in the region where mosquitoes carry West Nile virus. Twenty of those sites are in Delaware County. Holli Senior is a spokeswoman for the Pennsylvania Department of Health.

Senior: It’s not uncommon for us to start seeing positive mosquito pools in the southern part of the state before other areas simply because the southern part of the state tends to warm up a little quicker than the northern tier.

So far, Philadelphia, Bucks, Montgomery, and Delaware counties have had positive mosquito samples. Amy Nardi is the assistant director of Delaware County’s Intercommunity Health Coordination. She says it’s not just West Nile that’s more prevalent — mosquitoes are too.

Nardi: When you have a large number of mosquitoes, the likelihood of finding the virus goes up. So because of the weather conditions and you have more mosquitoes, you’re more likely to find the virus present.

Nardi says a wet spring and a hot summer may have contributed to the population boom.

Some counties have begun spraying areas to kill mosquitoes. Nardi says as West Nile activity heats up through the summer, spraying will too. Health officials ask that people remove standing water such as bird baths, clogged gutters, and open trash cans to reduce mosquito breeding sites.