Pennsylvania launches West Nile virus surveillance program

Officials from the state departments of Agriculture, Environmental Protection and Health today joined representatives from Cumberland and Dauphin counties to launch Pennsylvania’s program to detect and control mosquitoes that carry West Nile virus. http://www.dsf.health.state.pa.us
 
“It’s that time of the year again for residents of the Commonwealth to remember West Nile virus and take steps to reduce their risk of infection,” said Health Secretary Dr. Calvin B. Johnson. “If you are going to be in an area with mosquito activity, remember to use insect repellant containing DEET especially during dawn and dusk.”

Last year, West Nile virus was found in all 67 counties. It was identified in 237 people with eight deaths. There were 546 birds, 953 mosquito pools, 100 sentinel chickens samples that tested positive. Also, there were 532 horses that became ill from infection. Very few of these horses had been vaccinated against West Nile virus. 

"Each year we learn how to battle West Nile more effectively,” Secretary of Environmental Protection Kathleen McGinty said. “This year, we are targeting a mosquito species, Culex restuans, early in the season. These mosquitoes don’t bite people, but they do bite birds and we think they played a significant role in spreading the virus among the bird population early last season. When other types of mosquitoes that bite people feed on these infected birds, the virus can be spread more widely to people. We hope by reducing the number of Culex restuans early in the season, we can reduce the spread of the virus among birds, and then among humans."

DEP and county West Nile coordinators will look for immature (larvae and pupae) and adult mosquitoes to determine if they are the species known to carry the virus, how many there are and their geographic distribution. To collect mosquitoes, DEP and county coordinators use equipment such as light traps, gravid traps and dippers. 

“Similar to people, horses only become infected with West Nile virus after being bitten by an infected mosquito,” Agriculture Secretary Dennis Wolff said. “We’re continuing to work with veterinarians and horse owners across the state to monitor horse populations. Horse owners should talk to their veterinarians about the vaccinations available for horses. It is wise to vaccinate early so that horses have time to build up immunity before the mosquitoes become active.”

Wolff added that horses are the only animals that can be vaccinated for WNV, since they seem to be the most susceptible to the illness. Pet owners can talk to their veterinarians about topical products that repel mosquitoes.

The Secretaries offer the following tips to eliminate mosquito-breeding sites around the home: 

• Identify and eliminate all sources of standing water that collects on your property. Mosquitoes will breed in any puddle that lasts for more than four days. 
• Dispose of tin cans, plastic containers, ceramic pots or similar water holding containers that have collected on your property. Do not overlook containers that have become overgrown by aquatic vegetation.
• Pay special attention to discarded tires that may have collected water on your property. They can serve as a breeding ground for mosquitoes.
• Drill holes in the bottom of recycling containers that are left out of doors. Drainage holes that are located on the container sides collect enough water for mosquitoes to breed in.
• Have clogged roof gutters cleaned on an annual basis, particularly if the leaves from surrounding trees have a tendency to block drains. 
• Turn over plastic wading pools when not in use. A wading pool becomes a place for mosquitoes to breed if it is not used on a regular basis.
• Turn over wheelbarrows and do not allow water to stagnate in birdbaths. 
• Aerate ornamental pools or stock them with fish. Water gardens are fashionable but become major mosquito breeding grounds if they are allowed to stagnate. 
• Keep swimming pools clean and chlorinated. A swimming pool that is left untended for a month becomes a source of mosquito breeding. Be aware that mosquitoes may even breed in the water that collects on swimming pool covers.

Dr. Johnson also reminded residents to report dead crows, blue jays and hawks by calling 1-877-PA-HEALTH toll-free, since they can be an indication that West Nile virus is present in an area.

Mosquitoes acquire the virus from infected birds. Those mosquitoes then transmit the virus to people and other animals. 

The virus, when transmitted to people, can cause West Nile Fever and Encephalitis, an infection that can cause an inflammation of the brain. Anyone can get the virus, but older adults and people with compromised immune systems have the highest risk of developing severe illness because their bodies have a harder time fighting off disease.
 
For more information about West Nile virus visit www.westnile.state.pa.us. Visitors can sign up to receive automatic updates about West Nile by e-mail. People can also call 1-877-PA-HEALTH for information.