title: Serological detection of exposure to Cryptosporidium parvum in cattle by ELISA and its evaluation in relation to coprological tests.
abstract: We evaluated serum examination as an alternative to fecal analysis for the diagnosis of exposure to Cryptosporidium parvum in cattle. The accuracy of the serum ELISA was compared to the combined results of concentration flotation microscopy and fecal enzyme immunoassay. The expected performance of the serum ELISA at different levels of infection with C. parvum was evaluated using the predicative values positive and negative. Optimal conditions for the serum ELISA can be achieved by diluting the serum samples 1:20 and the conjugate 1:8,000. The serum ELISA had a relatively high sensitivity of 97.5% (95% CI=87-100%) and poor specificity, 4% (95% CI=1-20%). There was a poor agreement between the serum ELISA and the fecal tests (kappa=0) on samples collected from adult cows in a high-risk and a low-risk population. Examination of some of these fecal samples using a PCR detection method demonstrated the presence of C. parvum DNA in 10% of the samples.
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, Section of Epidemiology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Daryl V
authors.initials: DV
authors.lastname: Nydam
authors.forename: Gabriella
authors.initials: G
authors.lastname: Lindergard
authors.forename: Charles L
authors.initials: CL
authors.lastname: Guard
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Schaaf
authors.forename: Susan E
authors.initials: SE
authors.lastname: Wade
authors.forename: Hussni O
authors.initials: HO
authors.lastname: Mohammed
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000276:immunology / Q000469:parasitology; D003457:Cryptosporidiosis / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D016785:Cryptosporidium parvum / Q000302:isolation & purification* / Q000472:pathogenicity; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005243:Feces / Q000166:cytology / Q000469:parasitology*; D006801:Humans; D010270:Parasite Egg Count / Q000662:veterinary; D011237:Predictive Value of Tests; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012698:Serologic Tests; D012987:Soil / Q000032:analysis / Q000469:parasitology
chemical_list: D000913:Antibodies, Protozoan; D012987:Soil