Pilot study assessing the effectiveness of long-lasting permethrin-impregnated clothing for the prevention of tick bites.
Journal: Vector-Borne and Zoonotic Diseases
Tick-borne diseases such as Lyme disease and Rocky Mountain spotted fever are a significant concern for many thousands of workers who have frequent and unavoidable exposure to tick infested habitats. Many North Carolina state employees with outdoor occupations report multiple tick bites each year, indicating that existing tick preventive strategies may be underutilized or ineffective. Treatment of clothing with permethrin, a nontoxic chemical with insecticidal, knockdown, and repellent properties, is highly effective against ticks.
However, most permethrin products must be reapplied after several washings in order to maintain insecticidal activity. Recently, a factory-based method for long-lasting permethrin treatment of clothing has been developed by Insect Shield, Inc. which allows clothing to retain insecticidal activity for over 70 washes.
A nonrandomized open label pilot study was conducted to determine the effectiveness of Insect Shield treated clothing for the prevention of tick bites among sixteen outdoor workers from the North Carolina Division of Water Quality under actual field conditions. Participants completed questionnaires at the start of follow-up (March, 2008) and at the end of follow-up (September, 2008), and tick bites and outdoor work hours were reported on weekly tick bite logs for the entire follow-up period.
Subjects wearing Insect Shield treated clothing had a 93% reduction (p<0.0001) in the total incidence of tick bites compared to subjects using standard tick bite prevention measures.
The rate of tick bites acquired during work hours was reduced by approximately 99% (p<0.0001) among subjects wearing Insect Shield treated clothing.
This study provides preliminary evidence that long-lasting permethrin-impregnated clothing may be highly effective against tick bites.