Tick-borne Illness and Clothing Study of Rhode Island

University of North Carolina (UNC)

Status

Completed

Conditions

Tick Bites

Tick-borne Diseases

Treatments

Other: Permethrin Impregnated Clothing

Study type

Interventional

Funder types

Other

Other U.S. Federal agency

Identifiers

NCT02613585

15-1770

R01OH010791 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

Lyme and other tick-borne diseases pose a significant health threat to outdoor workers. This study is a double-blind randomized controlled trial of outdoor workers in Rhode Island and the surrounding area that will address the following study aims: 1) Evaluate the effectiveness of LLPI clothing in preventing tick bites among outdoor workers in Lyme endemic areas; 2) Measure the urine levels of permethrin metabolites in study subjects; and 3) Measure the loss over time of knockdown activity against ticks and of permethrin in LLPI clothing.

Full description

Lyme and other tick-borne diseases pose a significant health threat to outdoor workers. In a double-blind randomized controlled trial (RCT) in North Carolina outdoor workers, the investigators previously showed that long-lasting permethrin-impregnated (LLPI) clothing provided >80% protection for one year against Lone Star tick bites among outdoor workers in North Carolina. But there are three issues that need to be addressed before this finding can be translated into policy: 1) Do LLPI clothing protect against black legged ticks, the vector for Lyme disease, babesiosis and anaplasmosis? 2) What levels of permethrin and its metabolites are absorbed, and are they potentially toxic? 3) Why did the LLPI clothing in our previous study lose efficacy after a year?

Participants: The investigators will recruit 250 outdoor workers. The investigators anticipate recruiting 80, 80, 40,30, and 20 participants from NationalGrid, the RI Department of Environmental Management, the Massachusetts Department of Conservation & Recreation, the National Park Service, and the US Fish & Wildlife Service.

Procedures (methods): This will be a randomized controlled trial. All study subjects will fill out weekly tick logs, collect attached ticks for later speciation and pathogen detection, and submit annual serum samples to test for exposure to tick-borne pathogens. A randomly selected subset of 60 subjects also will be asked to submit urine samples for permethrin metabolite analysis at several time points during follow-up. An additional randomly selected subset (n=30) will be asked to submit worn items of clothing for tick knockdown testing and permethrin content analysis at the end of the first and second years of field testing.

The results of this study could help protect hundreds of thousands of outdoor workers with exposure to ticks and tick-borne pathogens.

Enrollment

135 patients

Sex

All

Ages

18+ years old

Volunteers

Accepts Healthy Volunteers

Inclusion criteria

over 18 years of age,
spending an average of 10 or more hours of outdoor work per week during peak tick season, and
completion of written informed consent.

Exclusion criteria

pregnancy or a planned pregnancy during the follow-up period (since exposure to an insecticide is involved),
non-English speakers, or
having a known allergy or sensitivity to insecticides