The performance of the interferon gamma assay when used as a diagnostic or quality assurance test in Mycobacterium bovis infected herds
| Autor: | Eamonn Gormley, Tracy A. Clegg, Anthony Duignan, Simon J. More, Mairead B. Doyle, Margaret Good |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Veterinary medicine Databases Factual Single intradermal comparative tuberculin test (SICTT) 040301 veterinary sciences Post-mortem Sensitivity and Specificity Bovine tuberculosis 0403 veterinary science Interferon-gamma 03 medical and health sciences Food Animals Animals Medicine Diagnostic Interferon gamma assay Mycobacterium bovis biology Tuberculin Test business.industry Interferon-gamma assay Diagnostic test 04 agricultural and veterinary sciences Blood collection Intradermal Tests biology.organism_classification Test (assessment) 030104 developmental biology Immunology Herd Cattle Animal Science and Zoology Autopsy business Ireland Tuberculosis Bovine Quality assurance |
| Zdroj: | Preventive Veterinary Medicine. 140:116-121 |
| ISSN: | 0167-5877 |
| Popis: | There are two different contexts in the Irish bTB eradication programme in which the interferon-gamma assay (IFN-γ) is applied. Firstly, the IFN-γ assay is applied routinely to high risk cohorts in herds with four or more reactors to the SICTT. The IFN-γ test is then carried out on blood samples submitted to the laboratory within 8 h of collection (diagnostic testing). Secondly, the use of the IFN-γ assay has recently been extended to test SICTT reactors as part of a general quality assurance (QA) scheme to monitor the performance of the SICTT. Blood samples from reactors are tested one day after blood collection (QA testing). In this study, we analysed the relative performance of the SICTT and IFN-γ when used in parallel as an 8 h diagnostic test and as a 24 h QA test on SICTT reactors. A total of 17,725 IFN-γ tests were included in the analysis (11,658 diagnostic tests and 6067 QA tests). Of the samples submitted for diagnostic testing, the proportion positive to IFN-γ decreased with the severity of interpretation of the SICTT result. Of the standard reactors that were tested with IFN-γ in the QA programme, 92.2% were positive to the IFN-γ test. Among animals that were SICTT −ve/IFN-γ +ve, 18.9% were positive at post-mortem compared to 11.8% of those that were SICTT +ve (standard reactor)/IFN-γ −ve. These results highlight the risk associated with retaining SICTT −ve/IFN-γ +ve animals, and suggest that prompt removal of these animals is necessary to reduce the potential for future transmission. |
| Databáze: | OpenAIRE |
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