West Nile Virus Identified in Mosquito Pool

WEST CHESTER, PA – The Chester County Health Department is informing residents that mosquito traps collected in Greenfield Park in West Chester Borough have tested positive for West Nile Virus (WNV).

The mosquito traps were placed in various locations in the municipalities as part of routine surveillance by Health Department officials. The Health Department will continue to monitor these areas as well as surrounding areas and will consider control activities when appropriate.

The chance of contracting WNV from an infected mosquito is small and chances of becoming seriously ill are even smaller, however, the Health Department recommends that individuals take personal precautions to minimize the possibility of being bitten by infected mosquitoes. This includes staying indoors at dawn or dusk when mosquitoes are most active, wearing long sleeve shirts and long pants when outside and using insect repellents when mosquitoes are active. The heightened concern will probably remain until the first frost which usually occurs in mid-October.



For more information about WNV, visit our website at www.chesco.org/health or call 610-344-6455.


The Health Department recommends the following precautions to help eliminate mosquito-breeding areas:

  • Dispose of open containers on your property that may collect water, such as tin cans, plastic containers, ceramic pots, etc.
  • Keep your property clear of old tires or avoid areas where they may be stored.
  • Drill holes in the bottom of outdoor recycling containers so that water will not collect.
  • Clean roof gutters, particularly if leaves from surrounding trees have a tendency to plug drains.
  • Turn over plastic wading pools when not in use.
  • Turn over wheelbarrows and don’t let water stagnate in birdbaths.
  • Aerate ornamental pools or stock them with fish.
  • Clean and chlorinate swimming pools when not in use. A swimming pool left untended by a family on vacation for a month can produce enough mosquitoes to result in neighborhood-wide complaints. Mosquitoes may even breed in the water that collects on pool covers.
  • For stagnant pools of water, homeowners can buy Bti products at lawn/garden, outdoor supply, home improvement and other stores. This naturally occurring bacterial product kills mosquito larvae but is safe for people, pets, aquatic life and plants.

In addition, take these simple precautions to prevent mosquito bites:

  • Make sure screens fit tightly over doors and windows to keep mosquitoes out of homes.
  • Consider wearing long-sleeved shirts, long pants and socks when outdoors, particularly when mosquitoes are most active at dawn and dusk, or in areas known for having large numbers of mosquitoes.
  • When possible, reduce outdoor exposure at dawn and dusk during the summer.
  • Use insect repellants. An effective repellant will contain DEET, picaridin, or oil of lemon eucalyptus. Always be sure to follow the manufacturer label directions. Consult with a pediatrician or family physician if you have questions about the use of repellant on children, as repellant is not recommended for children under the age of two months.

For more information on West Nile Virus, visit www.chesco.org/health or call 610-344-6455.