Wednesday, April 25, 2001

West Nile Virus

Georgia Takes Precautions to Prevent the Arrival of an Unwanted Guest

At some point last summer, you may have heard news reports about persons being infected by West Nile virus (WNV) in the New York area. There have been no reported cases of WNV in Georgia.

However, many Georgia agencies (including the Centers for Disease Control and the Georgia Department of Public Health) have been actively engaged in surveillance, and have put plans into effect to facilitate early intervention should this virus be detected in our state.

West Nile Virus was first discovered in Uganda in 1937 and has been commonly found in humans, birds, and other vertebrates in Africa, Eastern Europe, West Asia, and the Middle East. It is not known with certainty how long the virus has been in the U.S., but scientists at the CDC believe that it has most likely been in the Eastern U.S. since the early summer of 1999.

Humans, birds, and horses become infected by the bite of mosquitoes infected with WNV. Mosquitoes become infected when they feed on infected birds. These infected mosquitoes can then transmit West Nile virus to humans and animals while biting to take blood.

Infection in humans and animals caused by WNV can result in encephalitis (inflammation of the brain), which can be a serious medical condition. Most infections are mild however, and symptoms may include fever, headache, and body aches, and occasionally skin rash and swollen lymph glands.

More severe infections are marked by headache, high fever, neck stiffness, stupor, disorientation, muscle weakness, tremor, convulsions, paralysis, and rarely, death. Since the summer of 1999, there have been 79 human cases of West Nile encephalitis reported. Persons older than 50 years appear to have the highest risk of severe disease.

Since the disease is spread by the migration of infected birds, and mosquitoes (that need water to breed), scientists believe that there is a good possibility that WNV may spread further south from New York, and possibly into Georgia. The reason for this is that Georgia is a major migration route for birds traveling north.

We boast over 350 species of birds in the state. Georgia also has a subtropical climate with more than 700 miles of swampland in the Okefenokee Swamp alone; a 100-mile coastline, and a 2,344-mile shoreline that can provide excellent mosquito breeding grounds.

Therefore, a comprehensive surveillance and control project was begun in 2000, in which the Georgia Division of Public Health is actively engaged. Early detection will best enable Georgia to prevent outbreaks. To that end: active human surveillance, surveillance through mosquito control programs, and provisions for the collection and testing of dead birds is in full operation.

A special congressional appropriation provided funds for the implementation of this enhanced WNV surveillance and control project. Currently, the project includes Georgia, and 18 other states along the eastern, southeastern, and southern coasts.

Some important points to remember:

West Nile virus is transmitted by infected mosquitoes. However, even in areas where mosquitoes do carry the virus, very few mosquitoes ­ much less than 1 percent are infected. Less than 1 percent of people whom an infected mosquito does bite will become severely ill.

You cannot contract West Nile virus from another person, or by caring for a horse infected with it. It has not been found to be person-to-person, or animal-to-person transmittable.

There is no evidence that a person can get the virus from handling live or dead infected birds. However, persons should not handle any dead animals without using gloves or double plastic bags.

To reduce your risk, try to stay indoors at dawn, dusk, and in the early evening. These are peak times for mosquitoes to be about and feeding.

Wear long-sleeved shirts and long pants whenever you are outdoors for long periods in areas that mosquitoes are likely to be.

Spray clothing, and/or apply insect repellents to exposed skin carefully. Always read instructions carefully before using any insect repellant, especially on infants and children.

If you should find dead birds that do not appear to have been killed by another cause (i.e. animal, car): you may place the bird in doubled plastic bags (cover hands first) and bring it to the environmental health department; or you may call environmental health at 770-461-1178, ext. 5415.

Again: there have been no reports of West Nile Virus in Georgia. However, one of the essential public health services is to "Inform, educate, and empower people about health issues." Our hope is that by informing our community on the etiology and transmission of this disease, as well as the prevention efforts that are already in effect, we will prevent undue concern, and provide helpful information.

Much of the information contained in this article was obtained from the CDC Division of Vector-Borne Infectious Diseases website at www.cdc.gov/ncidod/dvbid/westnile/q&a.htm, and from a study done by Ayers, Casillas,Miller, Palumbo, Schaffer, and Yeagley for Emory University in 2000. If you have further questions, please access the above website, or contact the Health Department at 770-461-1178, ext. 5416 (physical health) or 5415 (environmental health).