The Department of Health today reported this year's first human case of West Nile virus in Pennsylvania. The individual is a 69-year-old man from Philadelphia County.
West Nile virus is spread to people and animals by infected mosquitoes. Usually, the infection does not result in any illness. Older adults and persons with compromised immune systems are at greatest risk of becoming ill after a West Nile infection.
A severe West Nile infection can cause encephalitis, an inflammation of the brain. People with encephalitis may experience high fever, headache, neck stiffness, disorientation, tremors, convulsions, paralysis, and coma. Anyone with any of these symptoms should immediately contact their health care provider.
A milder form of infection is known as West Nile fever. In addition to fever, people with this form of the disease may also experience headache, body aches, skin rash, and swollen lymph glands.
There is no specific treatment for West Nile virus. For severe cases, hospitalization is needed and illness can be associated with long-term disabilities and death.
Since West Nile was first identified in Pennsylvania in 2000, the virus has been found in all areas of the state and has returned each summer. Statistics from recent years include:
- 2009: no human cases in Pennsylvania.
- 2008: 14 human cases; one death.
- 2007: 10 human cases; no deaths.
- 2006: nine human cases; two deaths.
- 2005: 25 human cases; two deaths.
- 2004: 15 human cases; two deaths.
- 2003: 237 human cases; nine deaths.
The department recommended these simple precautions to prevent mosquito bites, particularly for those most at risk which include the elderly and those with compromised immune systems:
- Make sure screens fit tightly over doors and windows to keep mosquitoes out of your home;
- When possible, reduce outdoor exposure at dawn and dusk, the times of day when the mosquitoes that transmit West Nile virus are most active, during the warmer months of the year (usually April through October);
- Consider wearing long-sleeved shirts, long pants and socks when outdoors, particularly at dawn and dusk, or in areas known for having large numbers of mosquitoes;
- Use insect repellents according to the manufacturer's instructions. Effective repellents contain DEET. Consult a doctor if you have concerns about the use of repellent on young children, as repellent is not recommended for children under the age of two months. Two other insect repellants, Picaridin (KBR 3023) and oil of lemon eucalyptus, a plant based repellent, were tested against mosquitoes and provided protection similar to repellents with low concentrations of DEET.
Pennsylvanians can also reduce the risk of West Nile virus by eliminating the places where mosquitoes breed. Here are some simple steps that can be taken around the house:
- Dispose of tin cans, plastic containers, ceramic pots, discarded tires, or any object on your property that could collect standing water. Drill holes in the bottom of recycling containers left outdoors;
- Have roof gutters cleaned every year, particularly if the leaves from nearby trees have a tendency to clog the drains;
- Turn over plastic wading pools and wheelbarrows when not in use;
- Don't let water stagnate in birdbaths;
- Aerate ornamental pools or stock them with fish;
- Clean and chlorinate swimming pools and remove standing water from pool covers;
- Use landscaping to eliminate standing water that collects on your property; and
- Standing water that cannot be eliminated should be treated with Bti products, which are sold at outdoor supply, home improvement, and other stores. Bti is a naturally occurring bacterium that kills mosquito larvae but is safe for people, pets, aquatic life and plants.
For more information about West Nile virus, including current test results for mosquitoes, birds and horses, visit www.westnile.state.pa.us or call the Department of Health at 1-877-PA HEALTH.
Pennsylvania Department of Health