title: Evaluation of the effectiveness of insecticide treated materials for household level dengue vector control.
abstract: OBJECTIVE
  To assess the operational effectiveness of long-lasting insecticide treated materials (ITMs), when used at household level, for the control of Aedes aegypti in moderately infested urban and suburban areas.
  
  
  METHODS
  In an intervention study, ITMs consisting of curtains and water jar-covers (made from PermaNet) were distributed under routine field conditions in 10 clusters (5 urban and 5 suburban), with over 4000 houses, in Trujillo, Venezuela. Impact of the interventions were determined by comparing pre-and post-intervention measures of the Breteau index (BI, number of positive containers/100 houses) and pupae per person index (PPI), and by comparison with indices from untreated areas of the same municipalities. The effect of ITM coverage was modeled.
  
  
  RESULTS
  At distribution, the proportion of households with ≥1 ITM curtain was 79.7% in urban and 75.2% in suburban clusters, but decreased to 32.3% and 39.0%, respectively, after 18 months. The corresponding figures for the proportion of jars using ITM covers were 34.0% and 50.8% at distribution and 17.0% and 21.0% after 18 months, respectively. Prior to intervention, the BI was 8.5 in urban clusters and 42.4 in suburban clusters, and the PPI was 0.2 and 0.9, respectively. In both urban and suburban clusters, the BI showed a sustained 55% decrease, while no discernable pattern was observed at the municipal level. After controlling for confounding factors, the percentage ITM curtain coverage, but not ITM jar-cover coverage, was significantly associated with both entomological indices (Incidence Rate Ratio = 0.98; 95%CI 0.97-0.99). The IRR implied that ITM curtain coverage of at least 50% was necessary to reduce A. aegypti infestation levels by 50%.
  
  
  CONCLUSIONS
  Deployment of insecticide treated window curtains in households can result in significant reductions in A. aegypti levels when dengue vector infestations are moderate, but the magnitude of the effect depends on the coverage attained, which itself can decline rapidly over time.
authors.affiliation: Institute of Tropical Medicine, Antwerp, Belgium. vvanlerberghe@itg.be
authors.forename: Veerle
authors.initials: V
authors.lastname: Vanlerberghe
authors.forename: Elci
authors.initials: E
authors.lastname: Villegas
authors.forename: Milagros
authors.initials: M
authors.lastname: Oviedo
authors.forename: Alberto
authors.initials: A
authors.lastname: Baly
authors.forename: Audrey
authors.initials: A
authors.lastname: Lenhart
authors.forename: P J
authors.initials: PJ
authors.lastname: McCall
authors.forename: Patrick
authors.initials: P
authors.lastname: Van der Stuyft
mesh_terms: D000330:Aedes / Q000187:drug effects / Q000254:growth & development*; D000818:Animals; D003140:Communicable Disease Control / Q000379:methods*; D003715:Dengue / Q000517:prevention & control*; D005191:Family Characteristics; D006302:Health Services Research; D006801:Humans; D057148:Insecticide-Treated Bednets; D007306:Insecticides / Q000494:pharmacology*; D009032:Mosquito Control / Q000379:methods*; D013383:Suburban Population; D014505:Urban Population; D014687:Venezuela
chemical_list: D007306:Insecticides