title: Insecticide resistance and the future of malaria control in Zambia.
abstract: BACKGROUND
  In line with the Global trend to improve malaria control efforts a major campaign of insecticide treated net distribution was initiated in 1999 and indoor residual spraying with DDT or pyrethroids was reintroduced in 2000 in Zambia. In 2006, these efforts were strengthened by the President's Malaria Initiative. This manuscript reports on the monitoring and evaluation of these activities and the potential impact of emerging insecticide resistance on disease transmission.
  
  
  METHODS
  Mosquitoes were captured daily through a series of 108 window exit traps located at 18 sentinel sites. Specimens were identified to species and analyzed for sporozoites. Adult Anopheles mosquitoes were collected resting indoors and larva collected in breeding sites were reared to F1 and F0 generations in the lab and tested for insecticide resistance following the standard WHO susceptibility assay protocol. Annual cross sectional household parasite surveys were carried out to monitor the impact of the control programme on prevalence of Plasmodium falciparum in children aged 1 to 14 years.
  
  
  RESULTS
  A total of 619 Anopheles gambiae s.l. and 228 Anopheles funestus s.l. were captured from window exit traps throughout the period, of which 203 were An. gambiae malaria vectors and 14 An. funestus s.s.. In 2010 resistance to DDT and the pyrethroids deltamethrin, lambda-cyhalothrin and permethrin was detected in both An. gambiae s.s. and An. funestus s.s.. No sporozoites were detected in either species. Prevalence of P. falciparum in the sentinel sites remained below 10% throughout the study period.
  
  
  CONCLUSIONS
  Both An. gambiae s.s. and An. funestus s.s. were controlled effectively with the ITN and IRS programme in Zambia, maintaining a reduced disease transmission and burden. However, the discovery of DDT and pyrethroid resistance in the country threatens the sustainability of the vector control programme.
authors.affiliation: Ministry of Health, National Malaria Control Centre, Lusaka, Zambia.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Chanda
authors.forename: Janet
authors.initials: J
authors.lastname: Hemingway
authors.forename: Immo
authors.initials: I
authors.lastname: Kleinschmidt
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Rehman
authors.forename: Varsha
authors.initials: V
authors.lastname: Ramdeen
authors.forename: Faustina N
authors.initials: FN
authors.lastname: Phiri
authors.forename: Sarel
authors.initials: S
authors.lastname: Coetzer
authors.forename: David
authors.initials: D
authors.lastname: Mthembu
authors.forename: Cecilia J
authors.initials: CJ
authors.lastname: Shinondo
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Chizema-Kawesha
authors.forename: Mulakwa
authors.initials: M
authors.lastname: Kamuliwo
authors.forename: Victor
authors.initials: V
authors.lastname: Mukonka
authors.forename: Kumar S
authors.initials: KS
authors.lastname: Baboo
authors.forename: Michael
authors.initials: M
authors.lastname: Coleman
mesh_terms: D000293:Adolescent; D000818:Animals; D002648:Child; D002675:Child, Preschool; D009033:Culicidae / Q000187:drug effects* / Q000469:parasitology; D003634:DDT / Q000494:pharmacology; D005260:Female; D006801:Humans; D007223:Infant; D007303:Insect Vectors / Q000187:drug effects; D007305:Insecticide Resistance / Q000235:genetics / Q000502:physiology*; D007306:Insecticides / Q000494:pharmacology; D008288:Malaria / Q000517:prevention & control* / Q000635:transmission*; D008297:Male; D009570:Nitriles / Q000494:pharmacology; D026023:Permethrin / Q000494:pharmacology; D010963:Plasmodium falciparum / Q000472:pathogenicity; D011722:Pyrethrins / Q000494:pharmacology; D015024:Zambia / Q000453:epidemiology
chemical_list: D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; D026023:Permethrin; D003634:DDT; C037304:cyhalothrin