October 15, 2015
The U.S. Centers for Disease Control and Prevention’s National Institute for Occupational Safety and Health (CDC’s NIOSH) has awarded a four-year grant of more than $2 million to study Lyme disease prevention and exposure among outdoor workers in Rhode Island. Steven Meshnick, MD, PhD, professor of epidemiology at the UNC Gillings School of Global Public Health, is one of the principal investigators for the study.
Lyme disease and other tick-borne illnesses are a significant health concern for many, particularly workers in outdoor occupations who have frequent exposure to tick-infested habitats.
“We hope to show that tick-repellent clothing is a safe and cost-effective way to prevent Lyme disease,” Meshnick said.
The grant will provide funding over four years for a randomized controlled trial of the effectiveness of long-lasting permethrin-impregnated (LLPI) clothing in outdoor workers in preventing tick bites. Permethrin-treated clothing is available commercially at many outdoor retailers. Insect Shield, a company based in Greensboro, N.C., is a major supplier of such clothing and will treat the clothing to be worn by study participants.
Meshnick and co-principal investigator Thomas Mather, PhD, director of the Center for Vector-Borne Disease at the University of Rhode Island (Kingston), also will determine how much, if any, of the permethrin is absorbed through the skin and how long the protective effect of the clothing lasts under field conditions. Their findings could help workers determine which work practices and personal protective equipment are most likely to protect against ticks and tick-borne illnesses.
The incidence of tick-borne disease throughout the U.S. has doubled since 1991. Nationally, the CDC estimates about 300,000 cases of Lyme disease are diagnosed each year, and 95 percent of those cases occur in just 14 states, one of which is Rhode Island.
“If successful,” proclaimed the CDC’s grant announcement, “[this] research could provide strong and much-needed evidence that the long-lasting treatment of clothing with permethrin results in significant reductions in tick-borne diseases with little chance of toxicity.”
Meshnick and other colleagues previously have shown that Insect-Shield-treated clothing decreased tick bites among park and forestry workers in North Carolina by more than 80 percent. The new study aims to determine the effectiveness and safety of treated clothing in preventing bites from the black-legged tick, the primary carrier of Lyme disease.