title: Personal Protection of Permethrin-Treated Clothing against Aedes aegypti, the Vector of Dengue and Zika Virus, in the Laboratory.
abstract: The dengue and Zika viruses are primarily transmitted by Aedes aegypti mosquitoes, which are most active during day light hours and feed both in and outside of the household. Personal protection technologies such as insecticide-treated clothing could provide individual protection. Here we assessed the efficacy of permethrin-treated clothing on personal protection in the laboratory.
  
  
  
  The effect of washing on treated clothing, skin coverage and protection against resistant and susceptible Ae. aegypti was assessed using modified WHO arm-in-cage assays. Coverage was further assessed using free-flight room tests to investigate the protective efficacy of unwashed factory-dipped permethrin-treated clothing. Clothing was worn as full coverage (long sleeves and trousers) and partial coverage (short sleeves and shorts). Residual permethrin on the skin and its effect on mosquitoes was measured using modified WHO cone assays and quantified using high-pressure liquid chromatography (HPLC) analysis.
  
  
  
  In the arm-in-cage assays, unwashed clothing reduced landing by 58.9% (95% CI 49.2-66.9) and biting by 28.5% (95% CI 22.5-34.0), but reduced to 18.5% (95% CI 14.7-22.3) and 11.1% (95% CI 8.5-13.8) respectively after 10 washes. Landing and biting for resistant and susceptible strains was not significantly different (p<0.05). In free-flight room tests, full coverage treated clothing reduced landing by 24.3% (95% CI 17.4-31.7) and biting by 91% (95% CI 82.2-95.9) with partial coverage reducing landing and biting by 26.4% (95% CI 20.3-31.2) and 49.3% (95% CI 42.1-59.1) respectively with coverage type having no significant difference on landing (p<0.05). Residual permethrin was present on the skin in low amounts (0.0041mg/cm2), but still produced a KD of >80% one hour after wearing treated clothing.
  
  
  
  Whilst partially covering the body with permethrin-treated clothing provided some protection against biting, wearing treated clothing with long sleeves and trousers provided the highest form of protection. Washing treated clothing dramatically reduced protection provided. Permethrin-treated clothing could provide protection to individuals from Ae. aegypti that show permethrin resistance. Additionally, it could continue to provide protection even after the clothing has been worn. Field trials are urgently needed to determine whether clothing can protect against dengue and Zika.
authors.affiliation: Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom.|arctec, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: James
authors.initials: J
authors.lastname: Orsborne
authors.affiliation: Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Sarah
authors.initials: S
authors.lastname: DeRaedt Banks
authors.affiliation: Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Adam
authors.initials: A
authors.lastname: Hendy
authors.affiliation: SFRC, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Salvador A
authors.initials: SA
authors.lastname: Gezan
authors.affiliation: Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Harparkash
authors.initials: H
authors.lastname: Kaur
authors.affiliation: Department of Global Health and Epidemiology, Umea University, Umea, Sweden.|Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
authors.forename: Annelies
authors.initials: A
authors.lastname: Wilder-Smith
authors.affiliation: School of Biological and Biomedical Sciences, Durham University, Durham, United Kingdom.
authors.forename: Steve W
authors.initials: SW
authors.lastname: Lindsay
authors.affiliation: Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom.|arctec, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: James G
authors.initials: JG
authors.lastname: Logan
mesh_terms: D000330:Aedes; D000818:Animals; D003020:Clothing; D003715:Dengue / Q000635:transmission*; D005260:Female; D006801:Humans; D007302:Insect Repellents / Q000008:administration & dosage*; D007303:Insect Vectors; D026023:Permethrin / Q000008:administration & dosage*; D000071243:Zika Virus Infection / Q000635:transmission*
chemical_list: D007302:Insect Repellents; D026023:Permethrin