This article was originally published last year.

Update: The 2018 mosquito season is proving to be the worst the County has seen since 2012. On July 31 the Borough announced the it had received West Nile positives in the areas of:

  • Greenfield Park
  • College Avenue Pump Station (700 block of College Ave.)
  • Everhart Park
  • Kathy McBratnie Park
  • Marshall Square Park
  • 100 Block Magnolia Street
  • 500 Block of East Miner Street

These are in addition to positives reported near Green Field Park and on S. College Avenue. Conditions throughout the state are the same. The Pennsylvania Health Alert Network reported recently: “WNV-positive mosquito pool counts are higher at this point in the season than in any other year since surveillance began in 2000. Risk of human WNV infection is likely to remain elevated over the next several months.”  

So far the Borough has not sprayed for mosquitoes but current conditions put the town at a high risk level. Officials are monitoring all incoming positives closely, with much more activity the threat level could be raised to very high risk. At this level the County considers the levels too high to be acceptable and will spray as needed.

Should spraying be necessary, West Chester Borough will (according to the West Nile Response Plan) “disseminate spray date, time, location and personal precaution information to all residents through all communication outlets available 48 hours in advance of the spray.”

Additional surveillance data is available at”  and follow the Chester County Health Department for the latest updates.


The West Chester effort to eliminate unnecessary spraying of mosquitoes is back and this time, thankfully, with less aggressive yard signs. The community-lead movement, now in its third year, began with a petition which rapidly collected over 400 signatures from local residents who didn’t want to see parks and fields sprayed for mosquitoes.

The group sites research from other communities who have successfully eliminated pesticide programs by controlling mosquito populations before they have a chance to form. The group argues the spraying of mature mosquito populations is an ineffective method of control and potentially harmful to the natural environment and people in the community.

But what about West Nile Virus?

West Nile Virus is an arthropod-borne virus commonly spread by mosquitoes and often the reason communities cite for implementing mosquito spraying programs. While most people infected will never have any symptoms, twenty percent will suffer flu-like symptoms and less than one percent experiencing a serious neurological reaction (Thank you CDC).

The County is reporting they identified they their first West Nile positive mosquito in a sample collected in East Goshen Township on May 25. No human cases of the virus have been reported this year. Last year there was one human case of West Nile Virus reported in Chester County. Over the last five years there have been a total of four human cases recorded in the county.

Not exactly epidemic numbers but spraying in critical situations has not been eliminated.
The County does on occasion spray adult mosquitoes but according to their website, “Spraying is done as a last resort after exhausting all other mosquito control strategies.”

In these situations the county reports using one of two Environmental Protection Agency-approved products, Permanone or DeltaGard.

Preventing a Confrontation

While, spraying is still an option it was not needed last year and the Don’t Spray Me team hopes to make that two year in a row.

Working with an extensive network of block captains they focus on prevention monitoring the Borough for areas of standing water including bird baths, pails, even trays under plants. According to these containers should be eliminated of water every three to five days for a bite-free, spray-free summer.

To learn more about mosquito prevention, join the growing or request a sign you can visit their website.

Curious about where the Borough stands on other environmental issues? We took a look at climate change.

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