title: Long-term acceptability, durability and bio-efficacy of ZeroVector®durable lining for vector control in Papua New Guinea.
abstract: This study examined the acceptability, durability and bio-efficacy of pyrethroid-impregnated durable lining (DL) over a three-year period post-installation in residential homes across Papua New Guinea (PNG).
  
  
  
  ZeroVector®ITPS had previously been installed in 40 homes across four study sites representing a cross section of malaria transmission risk and housing style. Structured questionnaires, DL visual inspections and group interviews (GIs) were completed with household heads at 12- and 36-months post-installation. Three DL samples were collected from all households in which it remained 36-months post-installation to evaluate the bio-efficacy of DL on Anopheles mosquitoes. Bio-efficacy testing followed WHO guidelines for the evaluation of indoor residual spraying.
  
  
  
  The DL was still intact in 86 and 39% of study homes at the two time periods, respectively. In homes in which the DL was still intact, 92% of household heads considered the appearance at 12-months post installation to be the same as, or better than, that at installation compared to 59% at 36-months post-installation. GIs at both time points confirmed continuing high acceptance of DL, based in large part of the perceived attractiveness and functionality of the material. However, participants frequently asserted that they, or their family members, had ceased or reduced their use of mosquito nets as a result of the DL installation. A total of 16 houses were sampled for bio-efficacy testing across the 4 study sites at 36-months post-installation. Overall, combining all sites and samples, both knock-down at 30 min and mortality at 24 h were 100%.
  
  
  
  The ZeroVector®DL installation remained highly acceptable at 36-months post-installation, the material and fixtures proved durable and the efficacy against malaria vectors did not decrease. However, the DL material had been removed from over 50% of the original study homes 3 years post-installation, largely due to deteriorating housing infrastructure. Furthermore, the presence of the DL installation appeared to reduce ITN use among many participating householders. The study findings suggest DL may not be an appropriate vector control method for large-scale use in the contemporary PNG malaria control programme.
authors.affiliation: Papua New Guinea Institute of Medical Research (PNGIMR), Goroka, EHP 441, Papua New Guinea.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Kuadima
authors.affiliation: Papua New Guinea Institute of Medical Research (PNGIMR), Goroka, EHP 441, Papua New Guinea.
authors.forename: Lincoln
authors.initials: L
authors.lastname: Timinao
authors.affiliation: Papua New Guinea Institute of Medical Research (PNGIMR), Goroka, EHP 441, Papua New Guinea.
authors.forename: Laura
authors.initials: L
authors.lastname: Naidi
authors.affiliation: Papua New Guinea Institute of Medical Research (PNGIMR), Goroka, EHP 441, Papua New Guinea.
authors.forename: Anthony
authors.initials: A
authors.lastname: Tandrapah
authors.affiliation: Swiss Tropical and Public Health Institute, PO Box 4002, Basel, Switzerland.|University of Basel, Petersplatz 1, 4003, Basel, Switzerland.
authors.forename: Manuel W
authors.initials: MW
authors.lastname: Hetzel
authors.affiliation: Papua New Guinea Institute of Medical Research (PNGIMR), Goroka, EHP 441, Papua New Guinea.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Czeher
authors.affiliation: Papua New Guinea Institute of Medical Research (PNGIMR), Goroka, EHP 441, Papua New Guinea. justin.pulford@lstmed.ac.uk.|Liverpool School of Tropical Medicine, Liverpool, Pembroke Place, Liverpool, l35QA, UK. justin.pulford@lstmed.ac.uk.
authors.forename: Justin
authors.initials: J
authors.lastname: Pulford
mesh_terms: D000818:Animals; D000852:Anopheles; D006798:Housing; D007306:Insecticides; D008288:Malaria / Q000517:prevention & control* / Q000523:psychology; D009032:Mosquito Control / Q000379:methods; D010219:Papua New Guinea; D020959:Polyethylene; D011722:Pyrethrins; D013997:Time Factors
chemical_list: D007306:Insecticides; D011722:Pyrethrins; D020959:Polyethylene
keywords: Durable lining; Papua New Guinea; Vector control