title: Serological evidence of discrete spatial clusters of Plasmodium falciparum parasites.
abstract: BACKGROUND
  Malaria transmission may be considered to be homogenous with well-mixed parasite populations (as in the classic Ross/Macdonald models). Marked fine-scale heterogeneity of transmission has been observed in the field (i.e., over a few kilometres), but there are relatively few data on the degree of mixing. Since the Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) is highly polymorphic, the host's serological responses may be used to infer exposure to parasite sub-populations.
  
  
  RESULTS
  We measured the antibody responses to 46 individual PfEMP1 domains at four time points among 450 children in Kenya, and identified distinct spatial clusters of antibody responses to individual domains. 35 domains showed strongly significant sero-clusters at p = 0.001. Individuals within the high transmission hotspot showed the greatest diversity of anti-PfEMP1 responses. Individuals outside the hotspot had a less diverse range of responses, even if as individuals they were at relatively intense exposure.
  
  
  CONCLUSIONS
  We infer that antigenically distinct sub-populations of parasites exist on a fine spatial scale in a study area of rural Kenya. Further studies should examine antigenic variation over longer periods of time and in different study areas.
authors: Centre for Geographic Medicine Research, Kenya Medical Research Institute/Wellcome Trust Programme, Coast, Kilifi, Kenya. pbejon@well.ox.ac.uk
authors: Philip
authors: P
authors: Bejon
authors: Louise
authors: L
authors: Turner
authors: Thomas
authors: T
authors: Lavstsen
authors: Gerald
authors: G
authors: Cham
authors: Ally
authors: A
authors: Olotu
authors: Chris J
authors: CJ
authors: Drakeley
authors: Marc
authors: M
authors: Lievens
authors: Johan
authors: J
authors: Vekemans
authors: Barbara
authors: B
authors: Savarese
authors: John
authors: J
authors: Lusingu
authors: Lorenz
authors: L
authors: von Seidlein
authors: Peter C
authors: PC
authors: Bull
authors: Kevin
authors: K
authors: Marsh
authors: Thor G
authors: TG
authors: Theander
mesh_terms: D000375:Aging / Q000276:immunology; D000818:Animals; D000917:Antibody Formation; D016000:Cluster Analysis; D006801:Humans; D007223:Infant; D008288:Malaria / Q000097:blood / Q000276:immunology / Q000469:parasitology* / Q000635:transmission*; D010963:Plasmodium falciparum / Q000276:immunology* / Q000472:pathogenicity; D025341:Principal Component Analysis; D015800:Protozoan Proteins / Q000276:immunology; D012698:Serologic Tests; D013997:Time Factors
chemical_list: D015800:Protozoan Proteins; C085731:erythrocyte membrane protein 1, Plasmodium falciparum