title: Evaluation of the SD FK70 malaria Ag Plasmodium vivax rapid diagnostic test in a non-endemic setting.
abstract: BACKGROUND
  For clinical and epidemiological reasons, it is interesting to diagnose non-falciparum malaria to the species level. This retrospective study assessed the performance of the SD BIOLINE Malaria Antigen Pv test (FK70), a two-band immunochromatographic test detecting Plasmodium vivax-specific lactate dehydrogenase, on samples of international travellers in a non-endemic setting.
  
  
  METHODS
  Stored blood samples from international travellers suspected of malaria were used, with microscopy corrected by PCR as the reference method. Samples infected by Plasmodium vivax (n = 100), Plasmodium falciparum (n = 75), Plasmodium ovale (n = 75) and Plasmodium malariae (n = 25) were included, as well as 100 malaria-negative samples. End points were sensitivity, specificity, inter-reader reliability and reproducibility.
  
  
  RESULTS
  The overall sensitivity of the FK70 for the diagnosis of P. vivax was 88.0% (95% confidence interval (CI): 83.6% - 90.3%). For parasite densities > 500/microl, a sensitivity of 97.2% (CI: 92.6% - 99.1%) was obtained. Specificity was 98.5%, with 4 out of 75 P. falciparum samples testing positive. None of the P. ovale samples tested positive. Nearly two-thirds (57/88, 64.7%) of positive P. vivax samples showed faint or weak line intensities, with stronger line intensities at higher parasite densities. The test showed excellent reproducibility and reliability for test results and line intensities (kappa values exceeding 0.98 and 0.87 respectively).
  
  
  CONCLUSIONS
  The FK70 test performed well in diagnosing P. vivax infections in a non-endemic reference setting. It can be of added value to microscopy in species differentiation of malaria infections, especially at parasite densities > 500/microl.
authors.affiliation: Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium. pgillet@itg.be
authors.forename: Philippe
authors.initials: P
authors.lastname: Gillet
authors.forename: Katrien
authors.initials: K
authors.lastname: Bosselaers
authors.forename: Lieselotte
authors.initials: L
authors.lastname: Cnops
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Bottieau
authors.forename: Marjan
authors.initials: M
authors.lastname: Van Esbroeck
authors.forename: Jan
authors.initials: J
authors.lastname: Jacobs
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000302:isolation & purification; D003955:Diagnostic Tests, Routine / Q000379:methods*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007770:L-Lactate Dehydrogenase / Q000302:isolation & purification; D016780:Malaria, Vivax / Q000175:diagnosis*; D015588:Observer Variation; D010966:Plasmodium vivax / Q000302:isolation & purification*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D000953:Antigens, Protozoan; D007770:L-Lactate Dehydrogenase