title: Effect of permethrin-impregnated underwear on body lice in sheltered homeless persons: a randomized controlled trial.
abstract: OBJECTIVE
  The control of body lice in homeless persons remains a challenge.
  
  
  OBJECTIVE
  To determine whether the use of long-lasting insecticide-treated underwear provides effective long-term protection against body lice in homeless persons.
  
  
  METHODS
  A randomized, double-blind, placebo-controlled trial was conducted in February and December 2011 in 2 homeless shelters (Madrague Ville and Forbin) in Marseille, France. Of the 125 homeless persons screened for eligibility, 73 body lice-infested homeless persons, 18 years or older, were enrolled.
  
  
  METHODS
  Body lice-infested homeless persons were randomly assigned to receive 0.4% permethrin-impregnated underwear or an identical-appearing placebo for 45 days, in a 1:1 ratio, with a permuted block size of 10. Visits were scheduled at days 14 and 45. Data regarding the presence or absence of live body lice were collected.
  
  
  METHODS
  The primary and secondary end points were the proportions of homeless persons free of body lice on days 14 and 45, respectively. Mutations associated with permethrin resistance in the body lice were also identified.
  
  
  RESULTS
  Significantly more homeless persons receiving permethrin-impregnated underwear than homeless persons receiving the placebo were free of body lice on day 14 in the intent-to-treat population (28% vs 9%; P = .04), with a between-group difference of 18.4 percentage points (95% CI, 1.4-35.4), and in the per-protocol population (34% vs 11%; P = .03), with a between-group difference of 23.7 percentage points (95% CI, 3.6-43.7). This difference was not sustained on day 45. At baseline, the prevalence of the permethrin-resistant haplotype was 51% in the permethrin group and 44% in the placebo group. On day 45, the permethrin-resistant haplotype was significantly more frequent in the permethrin group than in the placebo group (73% vs 45%, P < .001).
  
  
  CONCLUSIONS
  Permethrin-impregnated underwear is more efficient than placebo at eliminating body louse infestations by day 14; however, this difference was not sustained on day 45. The use of permethrin may have increased the resistance to permethrin in body lice and thus must be avoided.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT01287663.
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes, Aix-Marseille Université, Marseille, France2Institut Hospitalo-Universitaire Méditerranée Infection, Marseille, France.
authors.forename: Samir
authors.initials: S
authors.lastname: Benkouiten
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes, Aix-Marseille Université, Marseille, France2Institut Hospitalo-Universitaire Méditerranée Infection, Marseille, France3Service des Entérobactéries et Hygiène de l'Environnement, In.
authors.forename: Rezak
authors.initials: R
authors.lastname: Drali
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes, Aix-Marseille Université, Marseille, France.
authors.forename: Sékéné
authors.initials: S
authors.lastname: Badiaga
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes, Aix-Marseille Université, Marseille, France2Institut Hospitalo-Universitaire Méditerranée Infection, Marseille, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Veracx
authors.affiliation: Institut Hospitalo-Universitaire Méditerranée Infection, Marseille, France4Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, France.
authors.forename: Roch
authors.initials: R
authors.lastname: Giorgi
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes, Aix-Marseille Université, Marseille, France2Institut Hospitalo-Universitaire Méditerranée Infection, Marseille, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes, Aix-Marseille Université, Marseille, France2Institut Hospitalo-Universitaire Méditerranée Infection, Marseille, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Brouqui
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D003020:Clothing; D016001:Confidence Intervals; D004311:Double-Blind Method; D016503:Drug Delivery Systems / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005602:France; D006703:Ill-Housed Persons / Q000706:statistics & numerical data*; D006801:Humans; D007305:Insecticide Resistance / Q000187:drug effects; D007306:Insecticides / Q000009:adverse effects / Q000494:pharmacology; D010373:Lice Infestations / Q000188:drug therapy / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D010374:Pediculus / Q000472:pathogenicity*; D026023:Permethrin / Q000009:adverse effects / Q000494:pharmacology*; D012016:Reference Values; D018570:Risk Assessment; D016896:Treatment Outcome
chemical_list: D007306:Insecticides; D026023:Permethrin