title: Long-lasting permethrin impregnated uniforms: A randomized-controlled trial for tick bite prevention.
abstract: BACKGROUND
  Because of frequent exposure to tick habitats, outdoor workers are at high risk for tick-borne diseases. Adherence to National Institute for Occupational Safety and Health-recommended tick bite prevention methods is poor. A factory-based method for permethrin impregnation of clothing that provides long-lasting insecticidal and repellent activity is commercially available, and studies are needed to assess the long-term effectiveness of this clothing under field conditions.
  
  
  OBJECTIVE
  To evaluate the protective effectiveness of long-lasting permethrin impregnated uniforms among a cohort of North Carolina outdoor workers.
  
  
  METHODS
  A double-blind RCT was conducted between March 2011 and September 2012. Subjects included outdoor workers from North Carolina State Divisions of Forestry, Parks and Recreation, and Wildlife who worked in eastern or central North Carolina. A total of 159 volunteer subjects were randomized, and 127 and 101 subjects completed the first and second years of follow-up, respectively.
  
  
  METHODS
  Uniforms of participants in the treatment group were factory-impregnated with long-lasting permethrin whereas control group uniforms received a sham treatment. Participants continued to engage in their usual tick bite prevention activities.
  
  
  METHODS
  Incidence of work-related tick bites reported on weekly tick bite logs.
  
  
  RESULTS
  Study subjects reported 1,045 work-related tick bites over 5,251 person-weeks of follow-up. The mean number of reported tick bites in the year prior to enrollment was similar for both the treatment and control groups, but markedly different during the study period. In our analysis conducted in 2013, the effectiveness of long-lasting permethrin impregnated uniforms for the prevention of work-related tick bites was 0.82 (95% CI=0.66, 0.91) and 0.34 (95% CI=-0.67, 0.74) for the first and second years of follow-up.
  
  
  CONCLUSIONS
  These results indicate that long-lasting permethrin impregnated uniforms are highly effective for at least 1 year in deterring tick bites in the context of typical tick bite prevention measures employed by outdoor workers.
authors.affiliation: Department of Epidemiology, Gillings School of Global Public Health, Chapel Hill. Electronic address: meagan.vaughn@unc.edu.
authors.forename: Meagan F
authors.initials: MF
authors.lastname: Vaughn
authors.affiliation: Department of Epidemiology, Gillings School of Global Public Health, Chapel Hill.
authors.forename: Sheana Whelan
authors.initials: SW
authors.lastname: Funkhouser
authors.affiliation: Department of Biostatistics, Gillings School of Global Public Health, Chapel Hill.
authors.forename: Feng-Chang
authors.initials: FC
authors.lastname: Lin
authors.affiliation: Department of Biostatistics, Gillings School of Global Public Health, Chapel Hill; Department of Statistics, University of North Carolina at Chapel Hill, Chapel Hill.
authors.forename: Jason
authors.initials: J
authors.lastname: Fine
authors.affiliation: Division of Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill.
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Juliano
authors.affiliation: Department of Entomology, North Carolina State University, Raleigh, North Carolina.
authors.forename: Charles S
authors.initials: CS
authors.lastname: Apperson
authors.affiliation: Department of Epidemiology, Gillings School of Global Public Health, Chapel Hill.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Meshnick
mesh_terms: D000328:Adult; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D015994:Incidence; D007306:Insecticides / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009657:North Carolina; D026023:Permethrin / Q000008:administration & dosage*; D011481:Protective Clothing; D064927:Tick Bites / Q000517:prevention & control*; D017282:Tick-Borne Diseases / Q000517:prevention & control*
chemical_list: D007306:Insecticides; D026023:Permethrin