Lyme disease still No. 1 vector-borne illness

The number of cases of the tick-borne disease are increasing as people and animals continue on a collision course.

By Susan J. Landers, AMNews staff. Aug. 9, 2004.

Washington -- Scientists tracking ticks bearing pathogens employ many of the same techniques used by the crack team of Las Vegas crime scene investigators on the popular television series "CSI," with one important difference.

"Rather than determining whether a drop of blood found at the scene of the crime belongs to suspect A, B or C, we are looking to see if the DNA we extracted from a tick belongs to human pathogen A, B or C," said Richard Dryden, PhD, professor of biology at Washington and Jefferson College in Pennsylvania.

The pathogens he pursues are those that cause Lyme disease, babesiosis and human granulocytic ehrlichiosis, or HGE.

Lyme disease may have been bumped from the headlines by West Nile virus during the past few years, but it is still the most prevalent vector-borne disease in the United States.

The Centers for Disease Control and Prevention found there was a 40% increase in the incidence of Lyme disease, from 17,000 cases in 2001 to 23,763 cases 2002. Preliminary figures for 2003 -- totals have not yet been tallied -- forecast rates at a similar level.

Although the disease rarely causes death, the illness, especially if untreated, can be serious, resulting in facial palsy, meningitis or carditis.

Those bitten by an infected tick may also develop neurologic or joint abnormalities.

Dr. Dryden is beginning a four-year study funded by the CDC to help pinpoint areas in the Eastern United States where ticks are most heavily concentrated. The plan is for localities to take action to get rid of these "hot spots" and inform residents about their risk of contracting a tick-borne disease, said Dr. Dryden.