title: Insecticide-treated net (ITN) ownership, usage, and malaria transmission in the highlands of western Kenya.
abstract: BACKGROUND
  Insecticide-treated bed nets (ITNs) are known to be highly effective in reducing malaria morbidity and mortality. However, usage varies among households, and such variations in actual usage may seriously limit the potential impact of nets and cause spatial heterogeneity on malaria transmission. This study examined ITN ownership and underlying factors for among-household variation in use, and malaria transmission in two highland regions of western Kenya.
  
  
  METHODS
  Cross-sectional surveys were conducted on ITN ownership (possession), compliance (actual usage among those who own ITNs), and malaria infections in occupants of randomly sampled houses in the dry and the rainy seasons of 2009.
  
  
  RESULTS
  Despite ITN ownership reaching more than 71%, compliance was low at 56.3%. The compliance rate was significantly higher during the rainy season compared with the dry season (62% vs. 49.6%). Both malaria parasite prevalence (11.8% vs. 5.1%) and vector densities (1.0 vs.0.4 female/house/night) were significantly higher during the rainy season than during the dry season. Other important factors affecting the use of ITNs include: a household education level of at least primary school level, significantly high numbers of nuisance mosquitoes, and low indoor temperatures. Malaria prevalence in the rainy season was about 30% lower in ITN users than in non-ITN users, but this percentage was not significantly different during the dry season.
  
  
  CONCLUSIONS
  In malaria hypo-mesoendemic highland regions of western Kenya, the gap between ITNownership and usage is generally high with greater usage recorded during the high transmission season. Because of the low compliance among those who own ITNs, there is a need to sensitize households on sustained use of ITNs in order to optimize their role as a malaria control tool.
authors.affiliation: Climate and Human Health Research Unit, Centre for Global Health Research, Kenya Medical Research Institute, PO Box 1578-40100, Kisumu, Kenya. hatieli@yahoo.com
authors.forename: Harrysone E
authors.initials: HE
authors.lastname: Atieli
authors.forename: Guofa
authors.initials: G
authors.lastname: Zhou
authors.forename: Yaw
authors.initials: Y
authors.lastname: Afrane
authors.forename: Ming-Chieh
authors.initials: MC
authors.lastname: Lee
authors.forename: Isaac
authors.initials: I
authors.lastname: Mwanzo
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Githeko
authors.forename: Guiyun
authors.initials: G
authors.lastname: Yan
mesh_terms: D000293:Adolescent; D000818:Animals; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D019983:Guideline Adherence; D006801:Humans; D057148:Insecticide-Treated Bednets; D007306:Insecticides / Q000494:pharmacology; D007630:Kenya / Q000453:epidemiology; D008288:Malaria / Q000453:epidemiology* / Q000517:prevention & control* / Q000635:transmission; D008297:Male; D009032:Mosquito Control / Q000379:methods*; D010067:Ownership / Q000706:statistics & numerical data*; D015995:Prevalence; D011482:Protective Devices / Q000706:statistics & numerical data*
chemical_list: D007306:Insecticides