Gamma-interferon assay for the ancillary diagnosis of bovine tuberculosis in dairy cattle in urban and adjacent areas of Dhaka city, Bangladesh

Vet World Vol.16 October-2023 Article-14

Research Article

Veterinary World, 16(10): 2120-2127

https://doi.org/10.14202/vetworld.2023.2120-2127

Tanzida Begum Rumi¹, Sk. Shaheenur Islam^2,3, Robiul Islam⁴, Md. Mahmudul Hasan Faisal¹, S. M. Lutful Kabir², A. K. M. Anisur Rahman⁵, and Zeaur Rahim¹

1. International Center for Diarrhoeal Disease Research, Dhaka, Bangladesh.
2. Department of Microbiology and Hygiene, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh.
3. Department of Livestock Services, Ministry of Fisheries and Livestock, Dhaka-1215, Bangladesh.
4. Department of Microbiology, Jagannath University, Dhaka-1100, Bangladesh.
5. Department of Medicine, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh.

Background and Aim: Bovine tuberculosis (bTB) is an infectious disease of cattle, mainly caused by Mycobacterium bovis. This study aimed to evaluate the efficacy of the interferon-gamma (IFN-γ) assay and single-intradermal comparative tuberculin test (SICTT) in detecting bTB.

Materials and Methods: In an earlier study, 150 positive, 83 inconclusive, and 480 negative animals from 24 cattle herds were screened using SICTT. From these groups, 125 positive, 17 inconclusive, and six negative animals were subsequently verified using the IFN-γ assay. Single-intradermal comparative tuberculin test outcomes were interpreted according to standard guidelines, whereas blood samples were collected and stimulated with purified protein derivatives. Sandwich enzyme-linked immunosorbent assay was used to measure secreted IFN-γ. Concordant and Bayesian latent class analyses were performed to evaluate test performance.

Results: Results from the IFN-γ assay revealed that 83.2%, 64.7%, and 16.67% of the animals were positive in the SICTT-positive, inconclusive, and negative animal categories, respectively. Sensitivity (SE) and specificity (SP) of SICTT were 83.9% (95% confidence interval [CI]: 77.4-90.1) and 95.7% (95% CI: 86.9-99.7), respectively. Sensitivity and SP for the IFN-γ assay were 78.9% (95% CI: 71.9-85.4) and 83.9% (65.9-95.9), respectively. The use of both tests in parallel increases the SE of bTB detection (~94%), compared with SICTT alone.

Conclusion: Use of the IFN-γ assay with SICTT in parallel, predominantly on cattle demonstrating an inconclusive SICTT outcome, boosts bTB detection rate in low resource settings. Keywords: Bayesian latent class analysis, farmed dairy cattle, gamma-interferon assay, single-intradermal comparative tuberculin test.

Keywords: Bayesian latent class analysis, farmed dairy cattle, gamma-interferon assay, single-intradermal comparative tuberculin test.

How to cite this article: Rumi TB, Islam SS, Islam R, Faisal MMH, Kabir SML, Rahman AKMA, and Rahim Z (2023) Gamma-interferon assay for the ancillary diagnosis of bovine tuberculosis in dairy cattle in urban and adjacent areas of Dhaka city, Bangladesh, Veterinary World, 16(10): 2120-2127.

Received: 09-06-2023 Accepted: 17-09-2023 Published online: 17-10-2023

Corresponding author: S. M. Lutful Kabir E-mail: lkabir79@bau.edu.bd

DOI: 10.14202/vetworld.2023.2120-2127

Copyright: Rumi, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.