title: Use of an enzyme-linked immunosorbent assay in bulk milk to estimate the prevalence of Neospora caninum on dairy farms in Prince Edward Island, Canada.
abstract: This study evaluated the use of bulk milk as a diagnostic tool for estimation of herd-level Neospora caninum exposure in Atlantic Canada; it was used to estimate the prevalence of dairy farms with a within-herd N. caninum-seroprevalence > or = 15% in Prince Edward Island (PEI). The variation over time of N. caninum antibodies in bulk milk is also reported. Skimmed bulk milk and individual serum samples were analyzed for N. caninum antibodies by using an enzyme-linked immunosorbent assay (ELISA). Bulk milk samples were collected in May 2004 (n = 235), May 2005 (n = 189), and June 2005 (n = 235). The prevalence of dairy farms with a within-herd seroprevalence > or = 15% on PEI was 6.4% in May 2004. In May and June 2005, respectively, 10.1% and 10.2% of farms had a > or = 15% within-herd seroprevalence. In 11 farms that were considered positive based on bulk milk samples, blood samples were collected from all adult cows in September 2005, in conjunction with a 4th bulk milk sample on the same day. The correlation coefficient between serology and bulk milk ELISA was 0.87. The results of this study demonstrate that the prevalence of N. caninum in dairy farms can be estimated by using a bulk milk ELISA.
authors.affiliation: Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island C1A 4P3. wwapenaar@gmail.com
authors.forename: Wendela
authors.initials: W
authors.lastname: Wapenaar
authors.forename: Herman W
authors.initials: HW
authors.lastname: Barkema
authors.forename: Ryan M
authors.initials: RM
authors.lastname: O'Handley
authors.forename: Chris J M
authors.initials: CJ
authors.lastname: Bartels
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000032:analysis* / Q000097:blood; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis / Q000453:epidemiology*; D003048:Coccidiosis / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000592:standards / Q000662:veterinary*; D005260:Female; D008892:Milk / Q000276:immunology* / Q000382:microbiology; D018688:Neospora / Q000276:immunology*; D015995:Prevalence; D011325:Prince Edward Island / Q000453:epidemiology; D012680:Sensitivity and Specificity
chemical_list: D000913:Antibodies, Protozoan