Incidence Rates of Tickborne Illness are Rising

Ixodes scapularis (deer tick) adult female on left, nymph on right. Photos courtesy of Centers for Disease Control and Prevention, Marc C. Dolan, senior research biologist.

 

Americans are increasingly developing tickborne illnesses -- most commonly Lyme disease -- due to ever-changing ecosystems and continued residential development in the countryside. And because May through July is when most tick-borne infections occur, experts are reminding consumers now to use measures that can help prevent Lyme and other diseases from ticks.

People are moving into wooded rural areas, which are prime tick habitats around the country, says Marc Dolan, entomologist with the Centers for Disease Control and Prevention (CDC). He says there are a number of tickborne diseases in America and ticks can transmit multiple infections.

Dolan says Lyme, which is transmitted by the bite of a deer tick, is increasing also because the whitetail deer population, which is a host for the bacteria that cause Lyme disease, is growing and spreading geographically.

The CDC reports a dramatic increase in Lyme over the past decade, from 11,700 cases in 1995 to 21,304 last year. While reporting has improved, the CDC says Lyme still is greatly underreported. Most prevalent in the Northeast and upper Midwest, Lyme is found nationwide.

Tickborne diseases can be found all across the country, and Lyme has been reported in every state except Montana, says Pat Smith, president of the Lyme Disease Association. Two of her daughters developed Lyme and one became so ill she could not attend school for four years.

While Lyme disease can be devastating if not treated early, another tick-borne disease, Rocky Mountain spotted fever, can be fatal. RMSF is most common in the South, despite its name, with the highest incidence in North Carolina and Tennessee. U.S. cases increased dramatically to 1,843 last year from 695 in 2001.

Experts suggest some simple but effective measures to help protect against tick bites.

When youre in the woods, or even in your backyard, from early May to early July, when the nymphal (young) ticks that carry Lyme disease are most active, you should use a repellent such as DEET on exposed skin and clothing, Dolan says. Young ticks are very small and difficult to spot, which is another reason why Lyme disease is such a problem.

To repel ticks, the CDC recommends using DEET products with a concentration of 20 percent to 30 percent. Repellent makers say that, based on extensive testing, 15 percent DEET can repel ticks. Dolan suggests applying a permethrin-based product on clothing (permethrin should never be applied to skin). It is helpful to wear light-colored clothing to more easily spot ticks and wear long pants with the cuffs tucked under the socks.

Dolan strongly recommends performing a thorough tick check after coming indoors from a tick-infested area. Thats because if a tick is attached to the skin for less than 24 hours, the possibility of infection is extremely low. Tick checks involve closely examining clothing and skin for ticks, with special attention to the ears, in and around the hair, under the arms, behind the knees, around the waist and between the legs.

When an attached tick is found, its critical to detach it properly using tweezers because incorrect removal can make infection more likely. Visit www.cdc.gov/ncidod/ticktips2005/ for removal instructions.

Source: Kroeger Associates