title: Combining Synthetic Human Odours and Low-Cost Electrocuting Grids to Attract and Kill Outdoor-Biting Mosquitoes: Field and Semi-Field Evaluation of an Improved Mosquito Landing Box.
abstract: BACKGROUND
  On-going malaria transmission is increasingly mediated by outdoor-biting vectors, especially where indoor insecticidal interventions such as long-lasting insecticide treated nets (LLINs) are widespread. Often, the vectors are also physiologically resistant to insecticides, presenting major obstacles for elimination. We tested a combination of electrocuting grids with synthetic odours as an alternative killing mechanism against outdoor-biting mosquitoes.
  
  
  METHODS
  An odour-baited device, the Mosquito Landing Box (MLB), was improved by fitting it with low-cost electrocuting grids to instantly kill mosquitoes attracted to the odour lure, and automated photo switch to activate attractant-dispensing and mosquito-killing systems between dusk and dawn. MLBs fitted with one, two or three electrocuting grids were compared outdoors in a malaria endemic village in Tanzania, where vectors had lost susceptibility to pyrethroids. MLBs with three grids were also tested in a large semi-field cage (9.6 × 9.6 × 4.5m), to assess effects on biting-densities of laboratory-reared Anopheles arabiensis on volunteers sitting near MLBs.
  
  
  RESULTS
  Significantly more mosquitoes were killed when MLBs had two or three grids, than one grid in wet and dry seasons (P<0.05). The MLBs were highly efficient against Mansonia species and malaria vector, An. arabiensis. Of all mosquitoes, 99% were non-blood fed, suggesting host-seeking status. In the semi-field, the MLBs reduced mean number of malaria mosquitoes attempting to bite humans fourfold.
  
  
  CONCLUSIONS
  The improved odour-baited MLBs effectively kill outdoor-biting malaria vector mosquitoes that are behaviourally and physiologically resistant to insecticidal interventions e.g. LLINs. The MLBs reduce human-biting vector densities even when used close to humans, and are insecticide-free, hence potentially antiresistance. The devices could either be used as surveillance tools or complementary mosquito control interventions to accelerate malaria elimination where outdoor transmission is significant.
authors.affiliation: Environmental and Ecological Sciences Thematic Group, Ifakara Health Institute, Dar es Salaam, Tanzania.|Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Nancy S
authors.initials: NS
authors.lastname: Matowo
authors.affiliation: Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.|Centre for Opportunistic, Tropical and Hospital Infections, National Institute for Communicable Diseases, Johannesburg, South Africa.
authors.forename: Lizette L
authors.initials: LL
authors.lastname: Koekemoer
authors.affiliation: Environmental and Ecological Sciences Thematic Group, Ifakara Health Institute, Dar es Salaam, Tanzania.|Swiss Tropical and Public Health Institute, Basel, Switzerland.|University of Basel, Basel, Switzerland.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Moore
authors.affiliation: Environmental and Ecological Sciences Thematic Group, Ifakara Health Institute, Dar es Salaam, Tanzania.
authors.forename: Arnold S
authors.initials: AS
authors.lastname: Mmbando
authors.affiliation: Environmental and Ecological Sciences Thematic Group, Ifakara Health Institute, Dar es Salaam, Tanzania.
authors.forename: Salum A
authors.initials: SA
authors.lastname: Mapua
authors.affiliation: Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.|Centre for Opportunistic, Tropical and Hospital Infections, National Institute for Communicable Diseases, Johannesburg, South Africa.
authors.forename: Maureen
authors.initials: M
authors.lastname: Coetzee
authors.affiliation: Environmental and Ecological Sciences Thematic Group, Ifakara Health Institute, Dar es Salaam, Tanzania.|School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Fredros O
authors.initials: FO
authors.lastname: Okumu
mesh_terms: D000818:Animals; D009033:Culicidae / Q000145:classification / Q000502:physiology*; D005260:Female; D006801:Humans; D007299:Insect Bites and Stings / Q000517:prevention & control*; D057148:Insecticide-Treated Bednets; D008288:Malaria / Q000517:prevention & control*; D008297:Male; D009032:Mosquito Control / Q000191:economics / Q000295:instrumentation* / Q000379:methods; D009812:Odorants; D010675:Pheromones / Q000191:economics / Q000627:therapeutic use*; D013636:Tanzania
chemical_list: D010675:Pheromones; C010411:insect attractants