title: Comparison of four rapid diagnostic tests, ELISA, microscopy and PCR for the detection of Giardia lamblia, Cryptosporidium spp. and Entamoeba histolytica in feces.
abstract: OBJECTIVE
  Microscopy is the diagnostic reference standard for the detection of parasites, but it is labor-intensive and requires experience. Rapid diagnostic tests (RDTs) can provide an alternative to microscopy.
  
  
  METHODS
  RDTs from four different manufacturers were compared to enzyme-linked immunosorbent assay (ELISA), microscopy and/or parasite-specific real-time PCR: ImmunoCardSTAT!®CGE (Meridian Bioscience Inc., Cincinnati, Ohio, USA) (A), Crypto/Giardia Duo-Strip (Coris Bioconcepts, Gembloux, Belgium) (B), RIDA®QUICK Cryptosporidium/Giardia/Entamoeba Combi (R-BioPharm, Darmstadt, Germany) (C) and Giardia/Cryptosporidium Quik Chek (Techlab Inc., Blacksburg, Virginia, USA) (D).
  
  
  RESULTS
  Thirty frozen samples were analyzed retrospectively. For Giardia lamblia (n=12) and Cryptosporidium (n=12) sensitivities ranged from 58% (B), over 83% (A, C) to 100% (D) and from 92% (B) to 100% (A, C, D), respectively. Specificity for both G. lamblia and Cryptosporidium was 100% for all RDT brands. Sensitivity for Entamoeba histolytica (n=5) was 100%, while specificity reached 80% (A) to 88% (C). In a prospective study, fresh samples were tested. For G. lamblia (n=30), sensitivity ranged from 66% (B), over 79% (A) and 83% (C) to 100% (D) and specificity varied between 94% (D) and 100% (A, B, C). For Cryptosporidium (n=3), sensitivity was 100% for all brands except (B) (67%) and specificities were 95% (A, B), 98% (C) and 100% (D). E. histolytica (n=1) was detected by both (A) and (C), while specificity was 81% and 87% respectively.
  
  
  CONCLUSIONS
  RDTs can be a valuable tool when microscopic expertise is poor and in remote and outbreak settings where other techniques are often not available and rapid diagnosis is required.
authors.affiliation: Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium. Electronic address: dorienvdb@hotmail.com.
authors.forename: Dorien
authors.initials: D
authors.lastname: Van den Bossche
authors.affiliation: Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Lieselotte
authors.initials: L
authors.lastname: Cnops
authors.affiliation: Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Jacob
authors.initials: J
authors.lastname: Verschueren
authors.affiliation: Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Marjan
authors.initials: M
authors.lastname: Van Esbroeck
mesh_terms: D002846:Chromatography, Affinity; D003457:Cryptosporidiosis / Q000175:diagnosis; D003458:Cryptosporidium / Q000302:isolation & purification*; D016785:Cryptosporidium parvum / Q000302:isolation & purification*; D004748:Entamoeba histolytica / Q000302:isolation & purification*; D004749:Entamoebiasis / Q000175:diagnosis; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000469:parasitology*; D016829:Giardia lamblia / Q000302:isolation & purification*; D005873:Giardiasis / Q000175:diagnosis; D008853:Microscopy / Q000379:methods; D011446:Prospective Studies; D060888:Real-Time Polymerase Chain Reaction; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: Cryptosporidium; Entamoeba; Giardia; Rapid diagnostic tests