title: Multiplicity of Plasmodium falciparum infection predicts antimalarial treatment outcome in Ugandan children.
abstract: BACKGROUND
  In areas with intense malaria transmission, individuals are often simultaneously infected with multiple parasite strains. This study assessed the effect of multiple infections on treatment response in Ugandan children with uncomplicated malaria.
  
  
  METHODS
  Four hundred and seventy six blood specimens were analysed for parasite genetic diversity. The P.falciparum merozoite surface protein-2 (msp-2) was analysed to establish multiplicity of infection for pre and post treatment specimens.
  
  
  RESULTS
  There were 32 different msp-2 alleles, 15 corresponding to the IC/3D7 and 17 to the FC27 allelic family. The majority of the isolates (343, 72 %) were multiple infections resulting into an overall mean multiplicity of infection of 2.15 (SD+/-1.02). Children infected with multiple strains had nearly a 3-fold increase in treatment failure (Hazard Ratio = 2.8, 95 % CI: 1.5-5.3) compared to their age mates infected with a single strain.
  
  
  CONCLUSIONS
  Multiple-strain infection reduced response to antimalarial therapy. Strategies that reduce multiple-strain infections (intermitted presumptive treatment, indoor residual spraying, insecticide treated nets and efficacious drugs) are likely to improve antimalarial drug efficacy and reduce rate of spread of drug resistance.
authors.affiliation: College of Health Sciences, Makerere University, Kampala, Uganda. drdjkyabayinze@yahoo.com
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Kyabayinze
authors.forename: Charles
authors.initials: C
authors.lastname: Karamagi
authors.forename: Moses
authors.initials: M
authors.lastname: Kiggundu
authors.forename: Moses R
authors.initials: MR
authors.lastname: Kamya
authors.forename: Fred
authors.initials: F
authors.lastname: Wabwire-Mangen
authors.forename: Fred
authors.initials: F
authors.lastname: Kironde
authors.forename: Ambrose
authors.initials: A
authors.lastname: Talisuna
mesh_terms: D000483:Alleles; D000953:Antigens, Protozoan / Q000235:genetics / Q000378:metabolism; D000962:Antimalarials / Q000627:therapeutic use*; D002675:Child, Preschool; D004359:Drug Therapy, Combination; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007223:Infant; D053208:Kaplan-Meier Estimate; D016778:Malaria, Falciparum / Q000175:diagnosis / Q000188:drug therapy* / Q000235:genetics / Q000469:parasitology; D008297:Male; D010963:Plasmodium falciparum / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D016016:Proportional Hazards Models; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism; D012008:Recurrence; D016896:Treatment Outcome; D014454:Uganda / Q000453:epidemiology
chemical_list: D000953:Antigens, Protozoan; D000962:Antimalarials; D015800:Protozoan Proteins; C065974:merozoite surface protein 2, Plasmodium