Pennsylvania's first human cases of West Nile virus of 2012 have been detected.

A Franklin County woman is now recovering after being hospitalized with meningitis due to WNV. A Lancaster County woman is also recovering after contracting West Nile fever, the milder form of WNV.

Due to an unprecedented level of mosquitoes carrying the West Nile virus, the Department of Health strongly urges residents to minimize their exposure to mosquitoes.

"Pennsylvanians should take steps to eliminate mosquito breeding sites around their homes and prevent mosquito bites by using insect repellents," advised Secretary of Health Dr. Eli N. Avila. "This is even more important for older Pennsylvanians and people with weakened immune systems, since they are at the greatest risk of severe illness including encephalitis if they develop West Nile virus infection."

Statewide sampling shows higher numbers of WNV-infected mosquitoes than any other summer since monitoring began 10 years ago. This is likely due to last year's mild winter.

As a result, Pennsylvania could see a greater number of human illnesses in 2012 than in recent years. The risk for WNV infection is highest during August and September and will not end until the first hard frost.

The Department of Environmental Protection conducts regular surveillance and control to manage mosquito populations around the state. So far, DEP has detected WNV-infected mosquitoes in 42 counties. However, it is likely that WNV is present in other areas as well.

"DEP will continue monitoring and working, through our spray activities, to stop the spread of West Nile Virus around the state," DEP Secretary Mike Krancer said. "I encourage all Pennsylvanians to take appropriate precautions to help prevent the spread of West Nile virus."

The mosquitoes that transmit WNV breed in areas with standing and stagnant water. These can include urban catch basins, clogged gutters, discarded tires, poorly maintained swimming pools, flower pots and other types of plastic containers.

Simple steps to eliminate standing water around the home include:

Ÿ Remove tin cans, plastic containers, ceramic pots, discarded tires or any object that could collect standing water. Drill holes in the bottom of recycling containers left outdoors.

Ÿ Have roof gutters cleaned every year, particularly if the leaves from nearby trees have a tendency to clog the drains.

Ÿ Turn over plastic wading pools and wheelbarrows when not in use.

Ÿ Do not let water stagnate in birdbaths.

Ÿ Aerate ornamental pools, or stock them with fish.

Ÿ Clean and chlorinate swimming pools, and remove standing water from pool covers.

Ÿ Use landscaping to eliminate standing water that collects on your property.

Ÿ Treat standing water that cannot be eliminated with Bti products which are sold at outdoor supply, home improvement and other stores. Bti is a natural product that kills mosquito larvae, but is safe for people, pets, aquatic life and plants.

Although mosquitoes can bite at any time of day or night, they are most active at dawn and dusk. When outdoors, people can avoid mosquito bites by properly and consistently using DEET-containing insect repellents and covering exposed skin with lightweight clothing. To keep mosquitoes from entering a home, make sure window and door screens are in place and are in good condition.

DEP will continue to survey communities statewide to monitor the size and scope of the WNV. When necessary, DEP will conduct larval and adult control activities in order to lessen the threat to human health. These efforts will continue through the end of October.

For a fact sheet on WNV, including symptoms, visit the Department of Health's webpage, www.health.state.pa.us [1], and click on "West Nile Virus Fact Sheet" under "What's Hot."

For more information, including current test results for mosquitoes, birds and horses, visit www.westnile.state.pa.us [2] and click on the Pennsylvania map, or call 1-877-PA HEALTH.