Prevalence of bovine tuberculosis and distribution of tuberculous lesions in cattle slaughtered at Gondar, Northwest Ethiopia

ABSTRACT

Background

In Ethiopia, bovine tuberculosis (BTB) is a neglected disease that affects the economy and livelihoods of farmers. However, the available data is limited due to insufficient disease surveillance in the country. Therefore; this study aimed to assess the prevalence and distribution of lesions of BTB in cattle slaughtered at Gondar, Northwest Ethiopia.

Methods

Postmortem examinations were used to detect tuberculous lesions, while smear microscopy and histopathology were performed for the identification of acid-fast bacilli (AFB).

Results

Of 497 inspected slaughtered cattle, 45 (9.1%, 95%CI; 0.0668–0.1193) were diagnosed with BTB suggestive tuberculous lesions. A higher proportion of gross lesions was recorded in lymph nodes of lungs; at the mediastinal (14, 31.1%) and bronchial (10, 22.2%) lymph nodes, and followed by mesenteric lymph nodes (9, 20%). Of 45 tuberculous lesions; only 2 (4.4%) were identified as AFB positive by smear microscopy and histopathology. In the overall statistical analysis, body conditions of slaughtered cattle were found to be significantly associated with BTB tuberculous lesions (p < 0.05).

Conclusion

This finding provides the prevalence of BTB and distribution of tuberculous lesions in cattle slaughtered at the abattoir and highlights the need for a practicable control strategy of the disease in the region.

KEYWORDS:

• Acid-fast bacilli
• cattle
• histopathology
• microscopy
• post-mortem inspection
• tuberculosis

Acknowledgments

The authors gratefully acknowledge the University of Gondar for funding this research project. Furthermore, staff members of the College of Veterinary Medicine and Animal Sciences to critically reviewing of the proposal and manuscript. Workers at the Gondar ELFORA abattoir, cattle owners, and butchery are highly appreciated for their cooperation during data collection.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Authors’ Contributions

Mebrat Ejo, Elias Kebede, and Abebe Belete generated the idea and designed the research. Mebrat Ejo, Selam Tilahun, Belete Haile, Yitayew Demessie, Gashaw Getaneh, and Abebaw Getachew performed the experiments. Mebrat Ejo, Seleshe Nigatu, and Abebe Belete moreover entered and analyzed data. Belete Haile, Seleshe Nigatu, and Mebrat Ejo contributed reagents and analysis tools. All the authors participated in the writing up of the manuscript as well as in the proofreading.

Ethics declaration

Ethical approval to conduct the study was obtained from the Institutional Review Board (IRB) of the University of Gondar, Ethiopia. In addition, at times of the actual data collection, a research support letter was obtained from the College of Veterinary Medicine and Animal Sciences, University of Gondar, Ethiopia.

Additional information

Funding

This study was funded by the University of Gondar, as part of the Mega Research Project with the grant number of VP/RCS/05/442/2017.

Notes on contributors

Abebe Belete

Dr. Abebe Belete Bitew graduated from Jimma University in 2014. He got his first degree in Doctor of Veterinary Medicine (DVM) and his master’s degree in Master of Public Health (MPH) from the School of Public Health, the University of Ghana in 2019. Since 2016, he is working as a full-time academician and researcher at the University of Gondar, Ethiopia. He has proven abilities in generating problem-solving research ideas and demonstrated skills in research design, data collection, data entry, data management, and data analysis (i.e. both quantitative and qualitative). He is also able to understand and interpret research outputs. He has a keen interest in the One Health Approach and Implementation science in resource-limited settings. He has expert-level ability in the use of STATA, R, and NVivo in quantitative and qualitative data analytics. Currently, he is working on a project titled “Assessment of existing slaughter facilities and effects of their effluents on human-animal and environment interface in Amhara Region, Ethiopia”

Selam Tilahun

Dr. Selam Tilahun was graduated from the University of Gondar in 2018. Since then, she is serving as a field veterinarian at Western Gondar Zone, Amhara Region, Ethiopia. She has in-depth research and clinical interest in infectious diseases, especially zoonotic ones.

Belete Haile

Dr. Belete Haile is graduated from the University of Gondar in Veterinary Medicine (2012) and master’s degree in Tropical and Infectious Disease from Akililu Lemma Institute of Biology, Addis Ababa University, Ethiopia (2018). He has also obtained a specialized master’s degree in Integrated Health Risk Management (one health) from the University of Liege, Belgium on September 8, 2021. He is a staff member of the University of Gondar working as an Assistant professor of Infectious Diseases. Belete Haile is currently a Ph.D. student at the City university of Hong Kong, performing research on infectious disease modeling.

Yitayew Demessie

Dr. Yitayew Demessie is a veterinarian and animal physiology specialist. He is serving as an academician and researcher at the College of Veterinary Medicine and Animal Sciences, University of Gondar. He has proven abilities in infectious diseases research and teaching experience. His academic preparation includes veterinary medicine, tropical infectious diseases, reproductive physiology and health, and farm animal production and health. He supervised DVM and MSc students and reviewed plenty of theses and mega projects.

Seleshe Nigatu

Dr. Seleshe Nigatu is an associate professor of Veterinary Public Health, and working as an academician and a senior researcher in the College of Veterinary Medicine and Animal Sciences, University of Gondar, Ethiopia. He has a huge experience in veterinary public health researches, educational quality audit and assurance, and One-health consortium. His research interest is on pathogens that have animal and human importance (zoonoses) and food-borne pathogens, their distribution, and drug sensitivity patterns. He did researches and advised DVM students on Methicillin-resistant Staphylococcus aureus (MRSA), Campylobacter jejuni, Brucella spp, Arcobacters, and various zoonotic foodborne parasitic diseases. He is an active member of the Ethiopian Veterinary Association, Ethiopian Public Health Association, Life Member of Indian Association of Veterinary Public Health (IAVPHS), and Life member of Indian Society for Advancement of Canine Practice (ICACP).

Abebaw Getachew

Dr. Abebaw Getachew Belay got his first degree in Doctor of Veterinary Medicine (DVM) in 2012 from Haramaya University Ethiopia, and Master of Public Health in Veterinary Public Health (MPH-VPH) from the University of Gondar in 2021. He has been engaged in teaching, research, and community engagement activities at the University of Gondar. He worked on infectious diseases and implementation research. Currently, he is on the way to complete his second master’s degree in Master of Public with a specialty in Health policy and management (MPH-HPM) at the University of Zambia. He is also working on implementation research focused on tuberculosis.

Gashaw Getaneh

Dr. Gashaw Getaneh graduated from Addis Ababa University, Ethiopia with a Doctor of Veterinary Medicine (DVM), and Master of Biomedical Sciences (MSc), specialized in Vertebrate Morphology from the University of Antwerp, Belgium. Currently, he is working as an assistant professor of Biomedical Sciences in the College of Veterinary Medicine and Animal Sciences at the University of Gondar, Ethiopia. He has been involved in teaching, research, and community engagement activities of the University. He supervised DVM and MSc students and reviewed plenty of theses and mega research projects of the college. He has an in-depth research interest in biomedical sciences and infectious pathogens, particularly on zoonotic diseases.

Elias Kebede

Dr. Elias Kebede graduated from Addis Ababa University, Ethiopia with a Doctor of Veterinary Medicine (DVM) in 2008, and a Master of Biochemistry (MSc) from the University of Malaya, Malaysia. He is working as an assistant professor of biochemistry in the College of Veterinary Medicine and Animal Sciences, University of Gondar, Ethiopia. He has been serving the college through teaching, research, and community engagement activities; and in leadership at the college level. He has worked on different mega research projects as a principal and co-investigator. He has supervised bachelor and master’s students at the college. He also reviewed college and university-wide research projects.

Mebrat Ejo

Dr. Mebrat Ejo graduated from Addis Ababa University, Ethiopia with a Doctor of Veterinary Medicine (DVM) in 2008, and a Master of Molecular Biology (MSc) from Katholic University Leuven, Belgium in 2013. He is working as an assistant professor of Molecular Biology in the College of Veterinary Medicine and Animal Sciences at the University of Gondar, Ethiopia. He has been involved in teaching, research, and community engagement activities of the University. He also worked in different laboratory protocols, particularly in a molecular genetic assay to study tuberculosis (DNA extraction, conventional PCR operations and result analysis, Spoligotyping for mycobacterial strain identification, GenoType DST for detection of resistant strains). Presently, he is working on the research study entitled molecular characterization of mycobacterial isolates causing tuberculosis in humans and animals in Northwest Ethiopia.