Objective. - Over 2 million adolescents participate in summer-camp experiences, placing themselves at risk for mosquito-borne illness. Insect repellent is recommended but often not used. It is unknown whether permethrin treatment of a location, such as a campsite, provides passive prophylaxis reducing mosquito bites among all persons in the immediate vicinity. Methods. - This randomized, double-blind controlled trial used 0.4% permethrin (2.5% permethrin diluted by 7 parts water) sprayed once onto the external surface of canvas tents at a Boy Scout summer camp. During a 9-week period, subjects (n = 545) completed nightly mosquito-bite and -landing counts for 5 minutes at dusk and recorded insect-repellent use within 2 hours of counting. Weekly mosquito sampling with CO2-baited Centers for Disease Control and Prevention traps occurred at study campsites. The primary outcome measure was the number of mosquito bites per 5 minutes. Results. - A total of 1614 person nights averaged 5.1 ± 7.2 (±SD) mosquito bites per 5 minutes. The permethrin-treated campsites had decreased mosquito landings and bites (relative risk reduction [RRR] 44%; 95% CI 34% to 55%; P < .001) compared with controls. Insect repellent was used only 32% of nights, decreasing bites by 36% (RRR 36%; 95% CI 25% to 47%; P < .001). Permethrin was superior to insect repellent alone (RRR 20%; 95% CI 4% to 37%; P = .01). Conclusions. - Permethrin treatment of tents is an effective, inexpensive public health measure to reduce mosquito bites. Permethrin is effective among all individuals in a camping setting and was more effective than topical insect repellent alone, which, although recommended, was inconsistently used.
|Original language||English (US)|
|Number of pages||7|
|Journal||Wilderness and Environmental Medicine|
|State||Published - 2005|
Bibliographical noteFunding Information:
The authors would like to thank the Indianhead Council of the Boy Scouts of America and Jim Schwieger in particular for allowing the study to be conducted at Tomahawk Scout Reservation; Greg Rohde (camp director) and Eric Solberg for onsite research coordination and mosquito sampling; David Neitzel, MS, of the Minnesota Department of Health for conceptual discussions; William Stauffer III, MD, DTM&H, for critical review of the manuscript; and Brad Benson, MD, for support of research at the University of Minnesota. There were no conflicts of interest because this study was self-funded.
- Randomized controlled trial
- West Nile virus