LEWISTOWN - For many, West Nile Virus has been brushed aside and placed in a file of things of the past. However, reports from Pennsylvania's West Nile Virus Control Program indicate that the virus has made a significant comeback this year.
On Monday, three mosquito samples tested positive for West Nile in Mifflin County, according to the Pennsylvania West Nile Virus Control Program. The positive samples were taken from Burnham Borough, Derry Township and Lewistown Borough, the organizatoin said. One avian sample from Juniata County tested positive along with one mosquito sample in Perry County, according to the organization. This year, Juniata County has had one avian and one veterinary case of West Nile virus, Mifflin County has had two avian cases and five mosquito cases and Perry county has had four mosquito cases, the organization said.
Bert Lavan, Centre County West Nile Virus Program Coordinator, said that most of these positives have turned up within the last month or six weeks at the most. He explained that if a bird is found to be positive for WNV, biologists from the Department of Environmental Protection in Harrisburg will come to the area in which the bird was found and set mosquito traps. Out of the seven samples that have been collected in Mifflin County, five of them have tested positive for West Nile virus, he said.
Lavan said that the West Nile Virus Control Program began in Pennsylvania in 2000 when West Nile first showed up in the U.S. By 2003, the virus was rampant and there were more than 200 confirmed human cases in Pennsylvania, he said. Following 2003 the virus trailed off for several years and has just now started to bounce back, Lavan said.
Statewide sampling shows higher numbers of infected mosquitoes than any other summer since monitoring began 10 years ago. The cause of this is being attributed to last years mild winter and early spring, Lavan said. Mosquitoes were seen as early as March this year which is unusual. Basically that has allowed more time for mosquitoes to bite infected birds, become infected themselves, and possibly transfer the infection to humans or other animals.
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, a milder form of the virus, the WNVCP said.
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. Residents should take steps to eliminate mosquito breeding sites around their homes and prevent mosquito bites by using insect repellant. This is more important for older residents and people with weakened immune systems since they are at the greatest risk of severe illness if they develop West Nile virus infection, the Department of Health said. As a result, Pennsylvania could see a greater number of human illnesses in 2012 than in recent years. The risk for infection is highest during August and September and will not end until the first hard frost, the Department of Health said.
The Department of Environmental Protection conducts regular surveillance and control to manage mosquito populations around the state. So far, DEP has detected infected mosquitoes in 42 counties. However, it is likely that West Nile virus is present in other areas as well, the DEP said.
The mosquitoes that transmit West Nile virus 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, the DEP said.
Steps should be taken to eliminate standing water around the home. Roof gutters should be cleaned regularly to eliminate clogs, plastic wading pools and wheelbarrows should be turned over when they are not in use, bird baths and ornamental pools should not contain stagnant water, pools should be clean and chlorinated and standing water should be removed from pool covers. Standing water that cannot be eliminated for various reasons should be treated 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 and plants, the DEP said.
Although mosquitoes can bite at any time of day or night, they are most active at dawn and dusk. When outdoors, people can avoid bites by properly and consistently using insect repellant and covering exposed skin with lightweight clothing. To keep mosquitoes from entering a home, make sure window and door screens are in place and in good condition, the DEP said.
The DEP said it will continue to survey communities statewide to monitor the size and scope of West Nile virus. When necessary, the DEP said it 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, the DEP said.
For a fact sheet on WNV, including symptoms, please visit the Department of Health's webpage, www.health.state.pa.us, 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 and click on the Pennsylvania map, or call (877) PA-HEALTH.
To report a dead bird call the county coordinator's office. For Mifflin and Juniata counties, contact Christian Boyer at 705-4150.