Effect of permethrin-impregnated underwear on body lice in sheltered homeless persons: a randomized controlled trial
Authors: Roch Giorgi
Didier Raoult
Rezak Drali
Philippe Brouqui
Samir Benkouiten
Sékéné Badiaga
Aurélie Veracx
Journal: JAMA Dermatology (2014)
Discipline: CLINICAL MEDICINE
Keywords: body lice; homeless persons; long-lasting insecticide-treated underwear; permethrin; resistance
Affiliations: Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes, Aix-Marseille Université, Marseille, France2Institut Hospitalo-Universitaire Méditerranée Infection, Marseille, France, 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, Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes, Aix-Marseille Université, Marseille, France, Institut Hospitalo-Universitaire Méditerranée Infection, Marseille, France4Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, France

Abstract:  Importance: 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. Design, setting, and participants: 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. Interventions: 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. Main outcomes and measures: 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 &lt; .001). Conclusion and relevance: 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. Trial registration: clinicaltrials.gov Identifier: NCT01287663. 

Retracted: No

PubPeer comments:
 In this study, 125 homeless people recruited from shelters in Marseille were enrolled in a study on the effect of permethrin-impregnated underwear on body lice. The trial was registered under NCT01287663 here: https: clinicaltrials.gov ct2 show NCT01287663 The registered study appears to deviate a bit from the reported results, and I was wondering if the authors could please comment on that. * Oral dose of Ivermectin vs underwear impregnated with Permethrin On the registration page, the Study Description mentions:  *The investigators therefore conducted a randomized, double-blind, placebo-controlled trial to test the hypothesis that a single oral dose of ivermectin was effective in significantly reducing the prevalence of pruritus in a sheltered homeless population.* There is no mentioning of the real experimental treatment, which was the permethrin-impregnated underwear. The paper does mention  *If persistent live body lice were found at this visit, homeless persons were offered a single dose of oral ivermectin (12 mg)* - but that seems to be the regular clinical care, not the experimental part of the study. * Primary and secondary outcome measures On the registration page, both Primary and Secondary Outcome Measures state:  *Show that underwear soaked with permethrine in 8 % allow to reduce in a long-lasting way (J90 and J365) of 50 % the index of infestation and prevalency of the louses in the group treated with regard to the group placebo. [ Time Frame: 2 YEARS ]* Yet, the paper reported data from days 14 and 45, not day 90 and day 365. I suspect this has to do with difficult ways to follow up with homeless persons, but the authors have had years of studies performed with this group, so it is worth asking why they designed the study for these long intervals. Brought to my attention by a reader. , 
 My second question is about the IRB approval for this study, since homeless persons might be considered to be a  vulnerable population (i.e., vulnerable to coercion), similar to veterans or prisoners in the US, although IRB rules might differ per country. The paper states that the study was approved by  *our institutional review board (January 24, 2011; reference 2010-A01406-33)* , so I assumed that this was a number referring to IRB approval by the Aix-Marseille Universitu00e9 and or Institut Hospitalo-Universitaire Mu00e9diterranu00e9e Infection, both listed as author affiliations. Surprisingly, this IRB approval number is used for at least 17 studies, including this one. Although all of them involve homeless persons recruited from Marseille shelters, the studies themselves vary in terms of study protocols and treatment sample collection. The studies vary from collecting lice, treating subjects with drug-impregnated underwear (this study), filling out questionnaires, medical exams, to nasal and pharyngeal sampling, skin swabbing, blood draw, rectal samples, sputum collection, and chest X rays. Moreover, the studies were performed from 2011 to 2020, spanning almost 10 years. Would the authors be willing to share the original 2010 ethical approval application here? Did they get approval for all these different studies spanning 10 years, in one single application? It was pointed out to me that the IRB approval number listed above was not a local ethical approval, but the ANSM RCB authorization ID, as per  Informed consent was obtained from these subjects, and the study was approved by the u2018u2018Comitu00e9 de Protection des Personnes Sud Mediterranu00e9eu2019u2019 on January, 12, 2011 (ID RCB: 2010-A01406-33) , as mentioned in PLoS ONE 8(2): e58088. So perhaps the authors mixed up the approval numbers of the studies. Either way, it would be of interest to take away any concern whether studies on this vulnerable populations were all performed within the original IRB approval scope. Here is the list of 17 papers that all appear to share the same ethical approval number: * Rezak Drali et al. - Journal of Clinical Microbiology (2012) p. 2229u20132233 - DOI: 10.1128 JCM.00808-12 * Rezak Drali et al. - PLoS ONE 8(2): e58088 (2013) - DOI: 10.1371 journal.pone.0058088 * Samir Benkouiten et al. - JAMA Dermatol. 2014;150(3):273-279 (2014) - DOI: 10.1001 jamadermatol.2013.6398 * Rezak Drali et al - Infection, Genetics and Evolution 39 (2016) 225u2013231 - DOI: 10.1016 j.meegid.2016.02.008 * Tran Duc Anh Ly et al. - Emerging Infectious Diseases (2017) - DOI: 10.3201 eid2311.170516 * Tran Duc Anh Ly et al. - Clinical Microbiology and Infection 25 (2019) 249.e1e249.e6 - DOI: 10.1016 j.cmi.2018.04.032 * Tran Duc Anh Ly et al. - Front. Cell. Infect. Microbiol. 9:86 (2019) - DOI: 10.3389 fcimb.2019.00086 * Tran Duc Anh Ly et al. - Journal of Epidemiology and Global Health (2019) - DOI: 10.2991 jegh.k.190510.001 * Tran Duc Anh Ly et al. - Infection and Drug Resistance 2019:12 1139u20131151 - DOI: 10.2147 IDR.S202048 * Nadia Amanzougaghene et al. - Parasites Vectors (2020) 13:177 - DOI: 10.1186 s13071-020-04036-y * Tran Duc Anh Ly et al. - European Journal of Clinical Microbiology Infectious Diseases (2020) - DOI: 10.1007 s10096-020-03889-6 * Tran Duc Anh Ly et al. - Travel Medicine and Infectious Disease 36 (2020) 101768 - DOI: 10.1016 j.tmaid.2020.101768 * Tran Duc Anh Ly et al. - Vector-Borne and Zoonotic Diseases (2020) - DOI: 10.1089 vbz.2019.2603 * Tran Duc Anh Ly et al. - Acta Microbiologica et Immunologica Hungarica (2021) - DOI: 10.1556 030.2021.01346 * Tran Duc Anh Ly et al. - Journal of Epidemiology and Global Health (2021) - DOI: 10.2991 jegh.k.201009.001 * Tran Duc Anh Ly et al. - Journal of Infection Volume 82, Issue 1, January 2021, Pages 60-66 - DOI: 10.1016 j.jinf.2020.11.026 * Tran Duc Anh Ly et al. - European Journal of Clinical Microbiology Infectious Diseases (2021) - DOI: 10.1007 s10096-020-04127-9 ,