Pennsylvania's West Nile Virus Surveillance ProgramBypass Navigation
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Welcome to Pennsylvania's West Nile Virus Control Program!
Protecting Public Health Since 2000

   In 2000, West Nile virus appeared for the first time in Pennsylvania in birds, mosquitoes and a horse. To combat the spread of West Nile virus, which is transmitted by mosquitoes, Pennsylvania has developed a comprehensive network. This network, which covers all 67 counties, includes trapping mosquitoes, collecting dead birds and monitoring horses, people and, in past years, sentinel chickens. Please explore our site to find out more about how you can help, to learn about West Nile virus or the latest surveillance update from your area.


Bti for Home Use

State DEP and county mosquito control professionals have been using Bti, a naturally occurring bacteria, to kill mosquito larvae for years. This material is now becoming widely available for you to buy and use yourself at home.

Bti can be purchased in small, donut-shaped form, often called "mosquito dunks", which are useful in small areas of standing water, such as a birdbath or small puddle of water that may gather in a low spot on your property. A granular form of Bti is available, and effective for larger areas, such as backyard ponds.

Bti can be purchased in many lawn and garden, outdoor supply, and home improvement stores. The great thing about this bacteria is that it kills only mosquito and black fly larvae. It is not harmful to people, pets, aquatic life (such as fish) or plants.

The best way to control mosquitoes is still to get rid of standing water on your property. And, make sure you follow all label instructions carefully if you use Bti at home.


Selected by the Science Educators: Sci-Links

"Selected by the SciLinks program, a service of the National Science Teachers Association. © 2001"

Bird Reporting Between October 1 and April 30, dead birds may be reported online only. The birds will NOT be picked up.

Maps and Surveillance
Click Here for more Info on Surveillance

The map above shows the current distribution of West Nile Virus in Pennsylvania. This map is based on surveillance results from the 2012 surveillance season. Click the map for the latest statewide surveillance information.

Today's Positives

Click Here for All Human Cases

The Today's Positives section is updated daily at 2:00PM. Positives from the previous day are removed at 2:00PM. Please note that mosquito samples may consist of 1 or more mosquitoes of 1 or more species.


News Releases
Please feel free to browse all of our past News Releases by clicking on the link below.

Link Our Web Site to Yours


A multi-agency cooperative effort between:

PA Department of Environmental Protection PA Department of Health PA Department of Agriculture