title: Detection of Cryptosporidium oocysts in human fecal specimens by an indirect immunofluorescence assay with monoclonal antibodies.
abstract: An indirect fluorescence assay (IFA) with monoclonal antibodies developed for the detection of Cryptosporidium oocysts in fecal smears (Meridian Diagnostics, Inc., Cincinnati, Ohio) was compared with the Zeihl-Neelsen-modified acid-fast stain (MAFS) in 119 human fecal specimens collected between 1984 and 1987. The sensitivity of the IFA was 100%; all 56 specimens positive by MAFS exhibited fluorescence. There were 63 specimens negative for Cryptosporidium sp. by MAFS; of these, 61 were negative by IFA (97% specificity). This discrepancy may reflect an increased sensitivity of the IFA to detect oocysts that were not visualized by MAFS because of faint staining or a paucity of organisms. On average, the IFA required less time than the MAFS (1 versus 5 min, respectively) when only rare or few oocysts were present. Cost comparison of reagents showed the IFA to be three times more expensive. The IFA offers a reasonable alternative to the MAFS because of its high sensitivity and specificity, the simplicity of performing it and interpreting results, and its capability of providing a definitive diagnosis of Cryptosporidium oocysts.
authors.affiliation: Infectious Disease Service, Wilford Hall USAF Medical Center, San Antonio, Texas 78236-5300.
authors.forename: J
authors.initials: J
authors.lastname: Rusnak
authors.forename: T L
authors.initials: TL
authors.lastname: Hadfield
authors.forename: M M
authors.initials: MM
authors.lastname: Rhodes
authors.forename: J K
authors.initials: JK
authors.lastname: Gaines
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D003044:Coccidia / Q000302:isolation & purification*; D003457:Cryptosporidiosis / Q000175:diagnosis*; D003458:Cryptosporidium / Q000276:immunology / Q000302:isolation & purification*; D005243:Feces / Q000469:parasitology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D011237:Predictive Value of Tests; D011933:Reagent Kits, Diagnostic
chemical_list: D000911:Antibodies, Monoclonal; D011933:Reagent Kits, Diagnostic