title: Performance of parasitological and molecular techniques for the diagnosis and surveillance of gambiense sleeping sickness.
abstract: OBJECTIVE
  Recently, improvements have been made to diagnostics for gambiense sleeping sickness control but their performance remains poorly documented and may depend on specimen processing prior to examination. In a prospective study in the Democratic Republic of the Congo, we compared the diagnostic performance of several parasite detection techniques, immune trypanolysis and of m18S PCR on whole blood stored in a stabilisation buffer or dried on filter paper.
  
  
  METHODS
  Individuals with CATT whole blood (WB) titer ≥1∶4 or with clinical signs indicative for sleeping sickness were examined for presence of trypanosomes in lymph node aspirate (LNA) and/or in blood. Blood was examined with Capillary Centrifugation Technique (CTC), mini-Anion Exchange Centrifugation Technique (mAECT) and mAECT on buffy coat (BC). PCR was performed on whole blood (i) stored in guanidine hydrochloride EDTA (GE) stabilisation buffer and (ii) dried on filter paper, and repeatability and reproducibility were assessed. Immune trypanolysis (TL) was performed on plasma.
  
  
  RESULTS
  A total of 237 persons were included. Among 143 parasitologically confirmed cases, 85.3% had a CATT-WB titre of ≥1/8, 39.2% were positive in LNA, 47.5% in CTC, 80.4% in mAECT-WB, 90.9% in mAECT-BC, 95.1% in TL and up to 89.5% in PCR on GE-stabilised blood. PCR on GE-stabilised blood showed highest repeatability (87.8%) and inter-laboratory reproducibility (86.9%). Of the 94 non-confirmed suspects, respectively 39.4% and 23.4% were TL or PCR positive. Suboptimal specificity of PCR and TL was also suggested by latent class analysis.
  
  
  CONCLUSIONS
  The combination of LNA examination with mAECT-BC offered excellent diagnostic sensitivity. For PCR, storage of blood in stabilisation buffer is to be preferred over filter paper. TL as well as PCR are useful for remote diagnosis but are not more sensitive than mAECT-BC. For TL and PCR, the specificity, and thus usefulness for management of non-confirmed suspects remain to be determined.
authors.affiliation: Department of Parasitology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo; Department of Tropical Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo.
authors.forename: Dieudonné
authors.initials: D
authors.lastname: Mumba Ngoyi
authors.affiliation: Department of Parasitology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo.
authors.forename: Rosine
authors.initials: R
authors.lastname: Ali Ekangu
authors.affiliation: Department of Parasitology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo.
authors.forename: Marie France
authors.initials: MF
authors.lastname: Mumvemba Kodi
authors.affiliation: Department of Parasitology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo.
authors.forename: Patient Pati
authors.initials: PP
authors.lastname: Pyana
authors.affiliation: Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Fatima
authors.initials: F
authors.lastname: Balharbi
authors.affiliation: Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Decq
authors.affiliation: Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of the Congo.
authors.forename: Victor
authors.initials: V
authors.lastname: Kande Betu
authors.affiliation: Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of the Congo.
authors.forename: Wim
authors.initials: W
authors.lastname: Van der Veken
authors.affiliation: Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of the Congo.
authors.forename: Claude
authors.initials: C
authors.lastname: Sese
authors.affiliation: Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Joris
authors.initials: J
authors.lastname: Menten
authors.affiliation: Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Philippe
authors.initials: P
authors.lastname: Büscher
authors.affiliation: UMR 177 IRD-CIRAD INTERTRYP, Institut de Recherche pour le Développement, Montpellier, France.
authors.forename: Veerle
authors.initials: V
authors.lastname: Lejon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D002648:Child; D003430:Cross-Sectional Studies; D015023:Democratic Republic of the Congo; D019468:Disease Management; D059788:Dried Blood Spot Testing; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000469:parasitology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D010949:Plasma / Q000469:parasitology; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013048:Specimen Handling; D014347:Trypanosoma brucei gambiense / Q000302:isolation & purification*; D014353:Trypanosomiasis, African / Q000175:diagnosis* / Q000453:epidemiology*; D055815:Young Adult