title: Mosquito feeding assays to determine the infectiousness of naturally infected Plasmodium falciparum gametocyte carriers.
abstract: BACKGROUND
  In the era of malaria elimination and eradication, drug-based and vaccine-based approaches to reduce malaria transmission are receiving greater attention. Such interventions require assays that reliably measure the transmission of Plasmodium from humans to Anopheles mosquitoes.
  
  
  METHODS
  WE COMPARED TWO COMMONLY USED MOSQUITO FEEDING ASSAY PROCEDURES: direct skin feeding assays and membrane feeding assays. Three conditions under which membrane feeding assays are performed were examined: assays with i) whole blood, ii) blood pellets resuspended with autologous plasma of the gametocyte carrier, and iii) blood pellets resuspended with heterologous control serum.
  
  
  RESULTS
  930 transmission experiments from Cameroon, The Gambia, Mali and Senegal were included in the analyses. Direct skin feeding assays resulted in higher mosquito infection rates compared to membrane feeding assays (odds ratio 2.39, 95% confidence interval 1.94-2.95) with evident heterogeneity between studies. Mosquito infection rates in membrane feeding assays and direct skin feeding assays were strongly correlated (p<0.0001). Replacing the plasma of the gametocyte donor with malaria naïve control serum resulted in higher mosquito infection rates compared to own plasma (OR 1.92, 95% CI 1.68-2.19) while the infectiousness of gametocytes may be reduced during the replacement procedure (OR 0.60, 95% CI 0.52-0.70).
  
  
  CONCLUSIONS
  Despite a higher efficiency of direct skin feeding assays, membrane feeding assays appear suitable tools to compare the infectiousness between individuals and to evaluate transmission-reducing interventions. Several aspects of membrane feeding procedures currently lack standardization; this variability makes comparisons between laboratories challenging and should be addressed to facilitate future testing of transmission-reducing interventions.
authors.affiliation: Department of Immunity and Infection, London School of Hygiene & Tropical Medicine, London, United Kingdom. teun.bousema@lshtm.ac.uk
authors.forename: Teun
authors.initials: T
authors.lastname: Bousema
authors.forename: Rhoel R
authors.initials: RR
authors.lastname: Dinglasan
authors.forename: Isabelle
authors.initials: I
authors.lastname: Morlais
authors.forename: Louis C
authors.initials: LC
authors.lastname: Gouagna
authors.forename: Travis
authors.initials: T
authors.lastname: van Warmerdam
authors.forename: Parfait H
authors.initials: PH
authors.lastname: Awono-Ambene
authors.forename: Sarah
authors.initials: S
authors.lastname: Bonnet
authors.forename: Mouctar
authors.initials: M
authors.lastname: Diallo
authors.forename: Mamadou
authors.initials: M
authors.lastname: Coulibaly
authors.forename: Timoléon
authors.initials: T
authors.lastname: Tchuinkam
authors.forename: Bert
authors.initials: B
authors.lastname: Mulder
authors.forename: Geoff
authors.initials: G
authors.lastname: Targett
authors.forename: Chris
authors.initials: C
authors.lastname: Drakeley
authors.forename: Colin
authors.initials: C
authors.lastname: Sutherland
authors.forename: Vincent
authors.initials: V
authors.lastname: Robert
authors.forename: Ogobara
authors.initials: O
authors.lastname: Doumbo
authors.forename: Yeya
authors.initials: Y
authors.lastname: Touré
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Graves
authors.forename: Will
authors.initials: W
authors.lastname: Roeffen
authors.forename: Robert
authors.initials: R
authors.lastname: Sauerwein
authors.forename: Ashley
authors.initials: A
authors.lastname: Birkett
authors.forename: Emily
authors.initials: E
authors.lastname: Locke
authors.forename: Merribeth
authors.initials: M
authors.lastname: Morin
authors.forename: Yimin
authors.initials: Y
authors.lastname: Wu
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Churcher
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000852:Anopheles / Q000469:parasitology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007303:Insect Vectors; D016778:Malaria, Falciparum / Q000635:transmission*; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000472:pathogenicity*; D055815:Young Adult