Field evaluation of specific mycobacterial protein-based skin test for the differentiation of Mycobacterium bovis-infected and Bacillus Calmette Guerin-vaccinated crossbred cattle in Ethiopia.

Content Provider	Europe PMC
Author	Bayissa, Berecha Sirak, Asegedech Zewude, Aboma Worku, Adane Gumi, Balako Berg, Stefan Hewinson, R. Glyn Wood, James L. N. Jones, Gareth J. Vordermeier, H. Martin Ameni, Gobena the ETHICOBOTS consortium
Abstract	AbstractBovine tuberculosis (bTB) challenges intensive dairy production in Ethiopia and implementation of the test and slaughter control strategy is not economically acceptable in the country. Vaccination of cattle with Bacillus Calmette–Guerin (BCG) could be an important adjunct to control, which would require a diagnostic test to differentiate Mycobacterium bovis (M. bovis)‐infected and BCG‐vaccinated animals (DIVA role). This study describes an evaluation of a DIVA skin test (DST) that is based on a cocktail (DSTc) or fusion (DSTf) of specific (ESAT‐6, CFP‐10 and Rv3615c) M. bovis proteins in Zebu–Holstein–Friesians crossbred cattle in Ethiopia. The study animals used were 74 calves (35 BCG vaccinated and 39 unvaccinated) aged less than 3 weeks at the start of experiment and 68 naturally infected ‘TB reactor’ cows. Six weeks after vaccination, the 74 calves were tested with the DSTc and the single intradermal cervical comparative tuberculin (SICCT) test. The TB reactor cows were tested with the DSTc and the SICCT test. Reactions to the DSTc were not observed in BCG‐vaccinated and unvaccinated calves, while SICCT test reactions were detected in vaccinated calves. DSTc reactions were detected in 95.6% of the TB reactor cows and single intradermal tuberculin positive reactions were found in 98.2% (95% confidence interval, CI, 92.1–100%). The sensitivity of the DSTc was 95.6% (95% CI, 87.6–99.1%), and significantly (p < .001) higher than the sensitivity (75%, 95% CI, 63.0–84.7%) of the SICCT test at 4 mm cut‐off. DSTf and DSTc reactions were correlated (r = 0.75; 95% CI = 0.53–0.88). In conclusion, the DSTc could differentiate M. bovis‐infected from BCG‐vaccinated cattle in Ethiopia. DST had higher sensitivity than the SICCT test. Hence, the DSTc could be used as a diagnostic tool for bTB if BCG vaccination is implemented for the control of bTB in Ethiopia and other countries.
Related Links	https://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC8801543&blobtype=pdf
Page Count	9
ISSN	18651674
Journal	Transboundary and Emerging Diseases [Transbound Emerg Dis]
Volume Number	69
DOI	10.1111/tbed.14252
PubMed Central reference number	PMC8801543
Issue Number	4
PubMed reference number	34331511
e-ISSN	18651682
Language	English
Publisher	John Wiley and Sons Inc.
Publisher Date	2021-08-19
Publisher Place	Hoboken
Access Restriction	Open
Rights License	This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2021 The Authors. Transboundary and Emerging Diseases published by Wiley‐VCH GmbH
Subject Keyword	BCG vaccination bovine tuberculosis crossbred cattle DIVA skin test specific mycobacterial proteins
Content Type	Text
Resource Type	Article
Subject	Immunology and Microbiology Veterinary Medicine