title: PCR and direct agglutination as Leishmania infection markers among healthy Nepalese subjects living in areas endemic for Kala-Azar.
abstract: OBJECTIVE
  To compare a PCR assay and direct agglutination test (DAT) for the detection of potential markers of Leishmania infection in 231 healthy subjects living in a kala-azar endemic focus of Nepal.
  
  
  METHODS
  The sample was composed of 184 (80%) persons without any known history of KA and not living in the same house as known kala-azar cases (HNK), 24 (10%) Healthy Household Contacts (HHC) and 23 (10%) past kala-azar cases which had been successfully treated (HPK).
  
  
  RESULTS
  PCR and DAT positivity scores were, respectively: HNK, 17.6% and 5.6%; HHC, 12.5% and 20.8%; HPK, 26.1% and 95.7%. The ratio PCR-positives/DAT-positives was significantly higher in HNK (ratio = 3.1) than in HHC (ratio = 0.6, P = 0.036) and in HPK (ratio = 0.2, P = 0.012). The ratio PCR-positives/DAT-positives did not significantly differ between HHC (ratio = 0.6) and HPK (ratio = 0.2, P = 0.473). The positive agreement index between PCR and DAT in HNK was 5%; in HHC, 0%; in HPK, 43%.
  
  
  CONCLUSIONS
  Our study highlights the specific character of PCR and DAT for the exploration of Leishmania asymptomatic infections. PCR is probably more informative for very recent infections among HNK, while DAT provides more information among HHC and HPK, a feature likely related to the power of serology to track less recent infections.
authors.affiliation: Unit of Molecular Parasitology, Institute of Tropical Medicine, Antwerpen, Belgium.
authors.forename: Narayan Raj
authors.initials: NR
authors.lastname: Bhattarai
authors.forename: Gert
authors.initials: G
authors.lastname: Van der Auwera
authors.forename: Basudha
authors.initials: B
authors.lastname: Khanal
authors.forename: Simonne
authors.initials: S
authors.lastname: De Doncker
authors.forename: Suman
authors.initials: S
authors.lastname: Rijal
authors.forename: Murari Lal
authors.initials: ML
authors.lastname: Das
authors.forename: Surendra
authors.initials: S
authors.lastname: Uranw
authors.forename: Bart
authors.initials: B
authors.lastname: Ostyn
authors.forename: Nicolas
authors.initials: N
authors.lastname: Praet
authors.forename: Niko
authors.initials: N
authors.lastname: Speybroeck
authors.forename: Albert
authors.initials: A
authors.lastname: Picado
authors.forename: Clive
authors.initials: C
authors.lastname: Davies
authors.forename: Marleen
authors.initials: M
authors.lastname: Boelaert
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Dujardin
mesh_terms: D000372:Agglutination Tests / Q000379:methods; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan; D015415:Biomarkers / Q000097:blood; D016054:DNA, Protozoan / Q000097:blood; D006801:Humans; D007893:Leishmania donovani / Q000302:isolation & purification; D007898:Leishmaniasis, Visceral / Q000175:diagnosis* / Q000453:epidemiology*; D008403:Mass Screening / Q000379:methods; D009390:Nepal; D016133:Polymerase Chain Reaction / Q000379:methods
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D015415:Biomarkers; D016054:DNA, Protozoan