URI researcher : Tick abundance running below average in Rhode Island, but Lyme disease risk still high

June 21, 2007

Deer tick abundance in Rhode Island is running 22 percent lower this year as compared to this same time last year, according to preliminary results from URI's statewide Tick Encounter Risk Survey. So far, the first of two planned samples have been collected at 40 of 61 sites distributed around the state.

Deer ticks transmit Lyme disease, babesiosis and anaplasmosis.

Thomas Mather, professor of entomology and director of URI's Center for Vector Borne Disease, said that the statewide survey of tick populations is finding that 60 percent of the sites surveyed have fewer ticks than last year.

"The remaining sites have found more ticks than last year, but in most cases there were only marginally more," Mather explained. "However, at sites in Jamestown, Burrillville and Johnston we found significantly more ticks than previously."

"Our research findings estimate that more than 717,000 Rhode Islanders are at potential risk for encountering a deer tick where they live," said Mather, whose tick surveillance program has resulted in the world's most comprehensive database on changes in the distribution and abundance of deer ticks. "Twenty years ago, the state's residents were largely free from this risk, unless they traveled to Prudence Island or Block Island." In 1993 when the survey first started, only 275,000 state residents risked encountering a deer tick where they lived.

Mather and his research and outreach team launched the nation's first tick bite prevention website - www.tickencounter.org - last year to provide residents and visitors with detailed information about tick biology, strategies for controlling ticks, health tips, and other information useful to anyone going outside in areas where ticks are abundant.

With the school year just ending, people will likely be spending more and more time outside. So, even though tick abundance is lower than last year, Mather recommends that all Rhode Islanders continue to take precautions to prevent contracting Lyme disease by routinely practicing personal protective measures and implementing tick control strategies around the yard.

Dr. Mather recommends:

• checking thoroughly every day for ticks;
• using a sharp tick removal tweezer to safely remove attached ticks;
• treating clothing with a repellent containing Permethrin and wearing the treated clothing whenever going in areas where ticks may lurk;
• keeping the edge of the yard clear of leaf litter because that's where people's exposure to ticks is most likely to occur; and
• hiring a trained professional pest controller or arborist to apply an appropriate tick treatment around the yard.

Adult deer ticks must be attached for 48 hours to transmit the Lyme disease pathogen, while nymphs, which are tiny and difficult to see, need only be attached for 24 hours to transmit a Lyme infection. It is the tiny nymphal stage that is active now.

Current Tick Activity in the Northeast United States

September update: Lone Star Tick Larva, also known as Seed Ticks, are beginning to emerge this month. Deer Tick Larvae are feeding on rodents. Rodents carry disease causing pathogens. By the beginning of September, there will be billions of these Deer Tick Larvae getting ready to molt into Nymphs! Watch a short video about this process on YouTube.

Current Tick Activity