title: Target product profiles for protecting against outdoor malaria transmission.
abstract: BACKGROUND
  Long-lasting insecticidal nets (LLINs) and indoor residual sprays (IRS) have decimated malaria transmission by killing indoor-feeding mosquitoes. However, complete elimination of malaria transmission with these proven methods is confounded by vectors that evade pesticide contact by feeding outdoors.
  
  
  METHODS
  For any assumed level of indoor coverage and personal protective efficacy with insecticidal products, process-explicit malaria transmission models suggest that insecticides that repel mosquitoes will achieve less impact upon transmission than those that kill them outright. Here such models are extended to explore how outdoor use of products containing either contact toxins or spatial repellents might augment or attenuate impact of high indoor coverage of LLINs relying primarily upon contact toxicity.
  
  
  RESULTS
  LLIN impact could be dramatically enhanced by high coverage with spatial repellents conferring near-complete personal protection, but only if combined indoor use of both measures can be avoided where vectors persist that prefer feeding indoors upon humans. While very high levels of coverage and efficacy will be required for spatial repellents to substantially augment the impact of LLINs or IRS, these ambitious targets may well be at least as practically achievable as the lower requirements for equivalent impact using contact insecticides.
  
  
  CONCLUSIONS
  Vapour-phase repellents may be more acceptable, practical and effective than contact insecticides for preventing outdoor malaria transmission because they need not be applied to skin or clothing and may protect multiple occupants of spaces outside of treatable structures such as nets or houses.
authors.affiliation: Biomedical and Environmental Thematic Group, Ifakara Health Institute, PO Box 53, Ifakara, Morogoro, United Republic of Tanzania. gkilleen@ihi.or.tz
authors.forename: Gerry F
authors.initials: GF
authors.lastname: Killeen
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Moore
mesh_terms: D006801:Humans; D007302:Insect Repellents / Q000494:pharmacology*; D057148:Insecticide-Treated Bednets; D007306:Insecticides / Q000494:pharmacology*; D008288:Malaria / Q000517:prevention & control* / Q000635:transmission*; D015233:Models, Statistical; D009032:Mosquito Control / Q000379:methods*
chemical_list: D007302:Insect Repellents; D007306:Insecticides