West Nile virus returns as summer's health buzz words

By Thomas Wilson
STAR STAFF
twilson@starhq.com

   A mosquito-borne virus that killed 284 Americans in 2002 -- including seven Tennesseans -- has health departments on alert for the summer season.
   West Nile virus infected over 4,000 people nationwide last year and health officials are bracing for a new round of expected infections this year.
   "We're not really sure how the season is going to progress," said Jamie Swift, regional director of communicable diseases at the regional health department office in Johnson City.
   The Tennessee Department of Health (TDOH) began testing and surveillance for West Nile virus last week in most counties of Tennessee.
   TDOH reported 56 residents tested positive for the virus in 2002, including one Johnson County resident. Forty of the positively tested humans lived in Shelby County. Seven Tennesseans died from WNV last year.
   The department's survey found the virus infected 824 birds and 141 horses. Three birds found in Carter County tested positive for the virus.
   WNV is carried by various species of birds that have high levels of the virus in their blood. Mosquitoes become infected when they feed on infected birds and can then transmit the virus to humans and horses through mosquito bites. WNV can occasionally cause meningitis or encephalitis in humans.
   TDOH reports persons over age 50 are at greatest risk for serious disease. Most human infections are mild, and symptoms include fever, headache and body aches that last only a few days. In more severe infections, victims suffer high fever, neck stiffness, stupor, disorientation, coma, convulsions, or paralysis.
   Swift said less than 1 percent of mosquitoes usually get West Nile and less than 1 percent of people bitten by mosquitoes carrying the virus suffer serious affliction from the disease.
   "Of the people who are bitten by mosquitoes, most will never know it," she said. "Most will never develop into West Nile virus." However, Swift says citizens need to be aware of the potential danger of West Nile and eliminate all breeding grounds for mosquitoes near the homes and businesses.
   The virus cannot spread from person to person and humans can not get the virus from birds. Swift said no cases of the virus in birds or horses had been reported through Friday. WNV is highly fatal among bluejays and crows. Local health departments are collecting freshly dead species of birds to be tested for West Nile virus.
   "After two to three positive results are found we will not continue to collect birds, because we'll know at that point it is in our county," said Caroline Hurt, director of the Carter and Johnson County health departments. Hurt said a "freshly dead" bird was characterized as being dead less than 24 hours and remaining intact.
   The Centers for Disease Control in Atlanta recommend citizens contact their local health department if they find a freshly dead crow or bluejay. If citizens find dead birds, the CDC advises using gloves or a plastic bag to collect the bird, double bag the carcass, and keep in a cool place until delivered or picked up by a health department official.
   A potential problem this year is the high levels of rainfall the Tri-Cities region experienced through the winter and spring seasons. Precipitation levels in the Tri-Cities area are 5.5 inches above normal with better than 22 inches of rain and snow measured through May 23, according to National Weather Service data. High water levels and frequent rainfall could create additional areas of standing water where mosquitoes love to breed.
   "You need to make sure to get rid of anything around your house that has standing water ... get rid of that breeding ground," Swift added.
   Elizabethton City Council has tentatively allocated $5,000 for mosquito eradication in the city's 2004 budget. Several council members stated during a recent budget workshop that the amount was far below what may be needed to control the insect.
   The state and regional health officials recommend residents take the following precautions to guard against exposure to mosquitoes:
   * Limit outdoor activities between dusk and dawn, if possible, since this is the time of greatest mosquito activity.
   * If you are outside when mosquitoes are prevalent, wear protective clothing such as long pants, long-sleeved shirts and socks.
   * Use a mosquito repellent that contains DEET (the chemical N-N-diethyl-meta-toluamide) and follow the directions on the label.