title: Multicentre studies of insecticide-treated durable wall lining in Africa and South-East Asia: entomological efficacy and household acceptability during one year of field use.
abstract: BACKGROUND
  Indoor residual spraying (IRS) is a primary method of malaria vector control, but its potential impact is constrained by several inherent limitations: spraying must be repeated when insecticide residues decay, householders can tire of the annual imposition and campaign costs are recurrent. Durable lining (DL) can be considered an advanced form of long-lasting IRS where insecticide is gradually released from an aesthetically attractive wall lining material to provide vector control for several years. A multicentre trial was carried out in Equatorial Guinea, Ghana, Mali, South Africa and Vietnam to assess the feasibility, durability, bioefficacy and household acceptability of DL, compared to conventional IRS or insecticide-treated curtains (LLITCs), in a variety of operational settings.
  
  
  METHODS
  This study was conducted in 220 households in traditional rural villages over 12-15 months. In all sites, rolls of DL were cut to fit house dimensions and fixed to interior wall surfaces (usually with nails and caps) by trained teams. Acceptability was assessed using a standardized questionnaire covering such topics as installation, exposure reactions, entomology, indoor environment, aesthetics and durability. Bioefficacy of interventions was evaluated using WHO cone bioassay tests at regular intervals throughout the year.
  
  
  RESULTS
  The deltamethrin DL demonstrated little to no decline in bioefficacy over 12-15 months, supported by minimal loss of insecticide content. By contrast, IRS displayed a significant decrease in bioactivity by 6 months and full loss after 12 months. The majority of participants in DL households perceived reductions in mosquito density (93%) and biting (82%), but no changes in indoor temperature (83%). Among those households that wanted to retain the DL, 73% cited protective reasons, 20% expressed a desire to keep theirs for decoration and 7% valued both qualities equally. In Equatorial Guinea, when offered a choice of vector control product at the end of the trial (DL, IRS or LLITCs), DL consistently emerged as the most popular intervention regardless of the earlier household allocation.
  
  
  CONCLUSIONS
  Just as long-lasting insecticidal nets overcame several of the technical and logistical constraints associated with conventionally treated nets and then went to scale, this study demonstrates the potential of DL to sustain user compliance and overcome the operational challenges associated with IRS.
authors.affiliation: Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK. louisa.messenger@lshtm.ac.uk
authors.forename: Louisa A
authors.initials: LA
authors.lastname: Messenger
authors.forename: Abrahan
authors.initials: A
authors.lastname: Matias
authors.forename: Antonio Nkulu
authors.initials: AN
authors.lastname: Manana
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Stiles-Ocran
authors.forename: Steve
authors.initials: S
authors.lastname: Knowles
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Boakye
authors.forename: Mamadou B
authors.initials: MB
authors.lastname: Coulibaly
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: Larsen
authors.forename: Amadou S
authors.initials: AS
authors.lastname: Traoré
authors.forename: Bréhima
authors.initials: B
authors.lastname: Diallo
authors.forename: Mamadou
authors.initials: M
authors.lastname: Konaté
authors.forename: Amadou
authors.initials: A
authors.lastname: Guindo
authors.forename: Sékou F
authors.initials: SF
authors.lastname: Traoré
authors.forename: Chris Eg
authors.initials: CE
authors.lastname: Mulder
authors.forename: Hoan
authors.initials: H
authors.lastname: Le
authors.forename: Immo
authors.initials: I
authors.lastname: Kleinschmidt
authors.forename: Mark
authors.initials: M
authors.lastname: Rowland
mesh_terms: D000349:Africa; D000818:Animals; D001210:Asia, Southeastern; D003692:Delayed-Action Preparations; D006798:Housing; D006801:Humans; D007306:Insecticides / Q000008:administration & dosage* / Q000009:adverse effects; D008288:Malaria / Q000517:prevention & control*; D009032:Mosquito Control / Q000379:methods*; D009570:Nitriles / Q000008:administration & dosage / Q000009:adverse effects; D010342:Patient Acceptance of Health Care; D011722:Pyrethrins / Q000008:administration & dosage / Q000009:adverse effects; D012424:Rural Population; D013784:Textiles / Q000032:analysis
chemical_list: D003692:Delayed-Action Preparations; D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; C017180:decamethrin