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Title: Aggregate testing for the evaluation of Johne's disease herd status.
Title Abreviation: Aust Vet J Date of Pub: 1996 Jan
Author: Jordan D;
Issue/Part/Supplement: 1 Volume Issue: 73 Pagination: 16-9
MESH Headings: Animal; Antibodies, Bacterial*; Cattle*; Cattle Diseases*; Data Collection*; Enzyme-Linked Immunosorbent Assay*; Mycobacterium tuberculosis*; Paratuberculosis*; Prevalence*; Random Allocation*; Sensitivity and Specificity*; -PG-;
Journal Title Code: 9IE Publication Type: JOURNAL ARTICLE
Date of Entry: 960729NEntry Month: 9610
Country: AUSTRALIA Index Priority: 2
Language: Eng Unique Identifier: 96261243
Unique Identifier: 96261243 ISSN: 0005-0423
Abstract: This paper examines methods for evaluating herd Johne's disease status that could be used in a survey of the cattle industry. Emphasis is placed on aggregate testing, a process whereby a random sample of cattle from a herd is assessed using an imperfect test, such as an ELISA for detecting antibody in serum. Important aggregate test parameters discussed include: sample size, herd-level sensitivity, herd-level specificity, the number of reactors used for declaring a positive herd result, and the expected within-herd prevalence of disease. Aggregate testing may be useful for several livestock diseases. However, problems arise when it is applied to Johne's disease because of the poor sensitivity of the available diagnostic tests, the low within herd prevalence of infection, and clustering of false positives within a herd.
Abstract By: Author
Address: New South Wales Agriculture, Queanbeyan.