Pennsylvania has reported its earliest detection of a West Nile virus-carrying mosquito since testing began in 2000, the Department of Environmental Protection said today. The first detection of 2011 was a mosquito collection in Morgan Township, Greene County, on May 17.
Certain mosquito species carry the virus, which may cause humans to contract West Nile encephalitis, an infection that can result in inflammation of the brain.
"After an unusually wet spring, high populations of adult mosquitoes have been detected in multiple areas," DEP Secretary Mike Krancer said. "Our staff will continue to monitor mosquito populations and will perform preventative spraying activities where necessary to reduce those populations and reduce the threat to public health."
West Nile virus was detected in 37 counties in 2010. There were 28 human cases reported statewide in 2010, the highest total of human cases since the all-time high of 236 cases in 2003. In 2004, Pennsylvania began its integrated pest management program, which has led to better identifying and controlling mosquito populations.
"Identifying West Nile virus so early in the season serves to remind us of the need to take steps to reduce exposure to mosquito bites and to eliminate places where mosquitoes can breed," Department of Health acting Physician General Stephen Ostroff said.
While most people do not get sick when infected with West Nile virus, everyone is at risk. Older adults and those with compromised immune systems have the highest risk of developing severe illness because their bodies have a harder time fighting off disease.
The best defense against the West Nile Virus is not giving them a place to breed. Mosquitoes lay their eggs in stagnant water around the home. Weeds, tall grass, shrubbery and discarded tires also provide an outdoor home for adult mosquitoes.
Individuals can take a number of precautionary measures around their homes to help eliminate mosquito-breeding areas, including:
- Dispose of cans, buckets, plastic containers, ceramic pots or similar containers that hold water on your property.
- Properly dispose of discarded tires that can collect water. Stagnant water is where most mosquitoes breed.
- Drill holes in the bottom of outdoor recycling containers.
- Have clogged roof gutters cleaned every year, particularly if the 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 not in use and remove any water that may collect on pool covers.
For stagnant pools of water, homeowners can buy Bti products at lawn and garden, outdoor supply, home improvement and other stores. This naturally occurring bacteria kills mosquito larva but is safe for people, pets, aquatic life and plants.
Additionally, these simple precautions can prevent mosquito bites, particularly for those who are most at risk:
- 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 peak mosquito periods, usually April through October.
- Use insect repellants according to the manufacturer's instructions. An effective repellant will contain DEET, picaridin, or oil of lemon eucalyptus. 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.
Pennsylvania Department of Environmental Protection