TY - JOUR
T1 - 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
AU - The ETHICOBOTS consortium
AU - Bayissa, Berecha
AU - Sirak, Asegedech
AU - Zewude, Aboma
AU - Worku, Adane
AU - Gumi, Balako
AU - Berg, Stefan
AU - Hewinson, R. Glyn
AU - Wood, James L.N.
AU - Jones, Gareth J.
AU - Vordermeier, H. Martin
AU - Ameni, Gobena
N1 - Funding Information:
This study was funded by the Biotechnology and Biological Sciences Research Council (BBSRC), the Department for International Development, the Economic & Social Research Council, the Medical Research Council, the Natural Environment Research Council and the Defense Science & Technology Laboratory, under the Zoonoses and Emerging Livestock Systems (ZELS) program, ref: BB/L018977/1. SB, RGH, HMV and GJJ were also partly funded by the Department for Environment, Food & Rural Affairs, United Kingdom, for this study, ref: TBSE3294. The funding bodies had no direct role in the design of the study and collection, analysis and interpretation of data and in writing the manuscript.
Publisher Copyright:
© 2021 The Authors. Transboundary and Emerging Diseases published by Wiley-VCH GmbH.
PY - 2022/7
Y1 - 2022/7
N2 - Bovine 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.
AB - Bovine 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.
KW - BCG vaccination
KW - DIVA skin test
KW - bovine tuberculosis
KW - crossbred cattle
KW - specific mycobacterial proteins
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U2 - 10.1111/tbed.14252
DO - 10.1111/tbed.14252
M3 - Article
C2 - 34331511
AN - SCOPUS:85127245164
SN - 1865-1674
VL - 69
SP - e1-e9
JO - Transboundary and Emerging Diseases
JF - Transboundary and Emerging Diseases
IS - 4
ER -