title: Is molecular biology the best alternative for diagnosis of malaria to microscopy? A comparison between microscopy, antigen detection and molecular tests in rural Kenya and urban Tanzania.
abstract: OBJECTIVE
  To assess the agreement of different diagnostic methods for the diagnosis and confirmation of the clinical suspicion of Plasmodium infection in children in Tanzania and Kenya.
  
  
  METHODS
  Blood samples were collected by the finger prick method from 338 children. Blood samples were collected from 338 children with the clinical suspicion of uncomplicated malaria in health clinics in Tanzania and Kenya. The presence of Plasmodium parasites was assessed with microscopy, rapid diagnostic tests (RDTs) and the molecular assays, quantitative nucleic acid sequence based amplification (QT-NASBA) and polymerase chain reaction (PCR). The results were compared and analysed for agreement.
  
  
  RESULTS
  There was a high degree of agreement (88.6-100%) between RDTs or molecular tests and microscopy. In rural Kenya, with a high incidence of malaria cases, the correlation coefficient ranged from 0.94 for RDTs to 0.76 for PCR. In urban Tanzania, where there was a low incidence of cases, R for RDTs was 1.0 but only 0.25 for PCR and 0.33 for NASBA.
  
  
  CONCLUSIONS
  Malaria is overestimated if the diagnosis is based solely on clinical signs. Therefore, laboratory confirmation is essential. Microscopy is a reliable method in rural areas where malaria is prevalent, but RDTs offer a good alternative with the advantage that it is an easy and rapid method. Molecular tests are more sensitive but difficult to implement in rural areas. In areas with lower incidence, molecular tests detect a significantly higher number of Plasmodium infections than RDTs or microscopy. Although implementation of molecular tools can be difficult, the prospect of an easy and cheap detection system makes them promising tools for the near future.
authors.affiliation: KIT Biomedical Research, Koninklijk Instituut voor de Tropen (KIT)/Royal Tropical Institute, Amsterdam, The Netherlands. p.mens@kit.nl
authors.forename: P
authors.initials: P
authors.lastname: Mens
authors.forename: N
authors.initials: N
authors.lastname: Spieker
authors.forename: S
authors.initials: S
authors.lastname: Omar
authors.forename: M
authors.initials: M
authors.lastname: Heijnen
authors.forename: H
authors.initials: H
authors.lastname: Schallig
authors.forename: P A
authors.initials: PA
authors.lastname: Kager
mesh_terms: D000953:Antigens, Protozoan / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D003955:Diagnostic Tests, Routine / Q000379:methods; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007630:Kenya / Q000453:epidemiology; D008288:Malaria / Q000175:diagnosis* / Q000453:epidemiology / Q000469:parasitology; D016778:Malaria, Falciparum / Q000175:diagnosis / Q000453:epidemiology / Q000469:parasitology; D008297:Male; D008853:Microscopy / Q000379:methods; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D010270:Parasite Egg Count; D016133:Polymerase Chain Reaction / Q000379:methods; D011446:Prospective Studies; D012423:Rural Health; D013636:Tanzania / Q000453:epidemiology; D014504:Urban Health
chemical_list: D000953:Antigens, Protozoan