title: How much does malaria vector control quality matter: the epidemiological impact of holed nets and inadequate indoor residual spraying.
abstract: BACKGROUND
  Insecticide treated nets (ITN) and indoor residual spraying (IRS) are the two pillars of malaria vector control in Africa, but both interventions are beset by quality and coverage concerns. Data from three control programs were used to investigate the impact of: 1) the physical deterioration of ITNs, and 2) inadequate IRS spray coverage, on their respective protective effectiveness.
  
  
  METHODS
  Malaria indicator surveys were carried out in 2009 and 2010 in Bioko Island, mainland Equatorial Guinea and Malawi to monitor infection with P. falciparum in children, mosquito net use, net condition and spray status of houses. Nets were classified by their condition. The association between infection and quality and coverage of interventions was investigated.
  
  
  RESULTS
  There was reduced odds of infection with P. falciparum in children sleeping under ITNs that were intact (Odds ratio (OR): 0.65, 95% CI: 0.55-0.77 and OR: 0.81, 95% CI: 0.56-1.18 in Equatorial Guinea and in Malawi respectively), but the protective effect became less with increasingly worse condition of the net. There was evidence for a linear trend in infection per category increase in deterioration of nets. In Equatorial Guinea IRS offered protection to those in sprayed and unsprayed houses alike when neighbourhood spray coverage was high (≥80%) compared to those living in areas of low IRS coverage (<20%), regardless of whether the house they lived in was sprayed or not (adjusted OR = 0.54, 95% CI 0.33-0.89). ITNs provided only personal protection, offering no protection to non users. Although similar effects were seen in Malawi, the evidence was much weaker than in Equatorial Guinea.
  
  
  CONCLUSIONS
  Universal coverage strategies should consider policies for repair and replacement of holed nets and promote the care of nets by their owners. IRS programs should ensure high spray coverage since inadequate coverage gives little or no protection at all.
authors.affiliation: MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Rehman
authors.forename: Mike
authors.initials: M
authors.lastname: Coleman
authors.forename: Christopher
authors.initials: C
authors.lastname: Schwabe
authors.forename: Giovanna
authors.initials: G
authors.lastname: Baltazar
authors.forename: Abrahan
authors.initials: A
authors.lastname: Matias
authors.forename: Irina Roncon
authors.initials: IR
authors.lastname: Gomes
authors.forename: Lee
authors.initials: L
authors.lastname: Yellott
authors.forename: Cynthia
authors.initials: C
authors.lastname: Aragon
authors.forename: Gloria Nseng
authors.initials: GN
authors.lastname: Nchama
authors.forename: Themba
authors.initials: T
authors.lastname: Mzilahowa
authors.forename: Mark
authors.initials: M
authors.lastname: Rowland
authors.forename: Immo
authors.initials: I
authors.lastname: Kleinschmidt
mesh_terms: D000293:Adolescent; D000818:Animals; D002648:Child; D002675:Child, Preschool; D016703:Equatorial Guinea; D006798:Housing; D006801:Humans; D007223:Infant; D007303:Insect Vectors; D007306:Insecticides; D008288:Malaria / Q000453:epidemiology* / Q000517:prevention & control*; D008295:Malawi; D015233:Models, Statistical; D009032:Mosquito Control / Q000379:methods*; D057147:Mosquito Nets; D016017:Odds Ratio; D010963:Plasmodium falciparum / Q000378:metabolism; D015995:Prevalence; D011634:Public Health; D011786:Quality Control
chemical_list: D007306:Insecticides