HARRISBURG – The Department of Health reported Pennsylvania’s first probable human case of West Nile virus (WNV) of 2011. On July 22, an elderly Lebanon County woman was hospitalized with a high fever and neurological symptoms. She is currently recovering.
WNV is spread to people and animals by infected mosquitoes. Usually, the infection does not result in any illness. However, older adults and persons with compromised immune systems are at an increased risk of becoming ill from a West Nile infection.
A severe West Nile infection can cause encephalitis or 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 milder 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 disease. For extreme cases, hospitalization may be required and associated with long-term disabilities and death.
This year, mosquito samples in 54 counties have been identified with West Nile virus.
It was first identified in Pennsylvania in 2000. Since then, the virus has been found in all areas of the state, returning each summer. Recent statistics show:
• 2010: 28 human cases; no deaths.
• 2009: No human cases.
• 2008: 14 human cases; one death.
• 2007: 10 human cases; no deaths.
• 2006: 9 human cases; two deaths.
• 2005: 25 human cases; two deaths.
• 2004: 15 human cases; two deaths.
• 2003: 237 human cases; nine deaths.
• 2002: 62 human cases; nine deaths.
• 2001: 3 human cases; no deaths.
To prevent mosquito bites, the department recommends doing the following:
• 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 mosquitoes that transmit WNV 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.
Exposure to infected mosquitoes can also be reduced by eliminating the places where mosquitoes lay their eggs. Steps to take around the house include:
• Dispose of 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;
• 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 leave 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 can be found 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 Pennsylvania Department of Health at 1-877-PA HEALTH.