Prevalence Study of Bovine Tuberculosis and Genus Typing of its Causative Agents in Cattle Slaughtered at Dilla Municipal Abattoir, Southern Ethiopia

Abstract

3 Abstract: A cross-sectional study was conducted at Dilla Municipal abattoir from December, 2012 to June 2013 to investigate the prevalence, associated risk factors and to identify the causative agents of Bovine tuberculosis (bTB) in Gedeo (Dilla Municipal abattoir), Southern Ethiopia. Postmortem examination, mycobacterial culturing and Multiplex genus typing techniques were employed. An overall prevalence of 2.6% (20/768) was recorded upon detailed post mortem examination with the major tuberculous lesions (75%) localized in the thoracic cavity (respiratory tract). Among the different risk factors analyzed, age (x2=12.4; P =0.002) and body condition (x2=35.7; P<0.001) were associated with bTB infection. Animals that have medium (OR=0.08; 95% CI: 0.02-0.43) and good body condition (OR=0.03; 95% CI: 0.01- 0.13) were less likely to have tubeculous lesions than poor body conditioned animals. Mycobacterial culture result revealed that growth was seen in 15 % (3/20) of the bTB suggestive lesions. Further Genus typing of the three culture positive isolates showed a band size of 1030bp for the two that represent Non Tuberculosis Mycobacterium species (NTM). While one isolate did not show a signal at all to the genus Mycobacterium. The study signified the importance of NTM in the formation of tuberculous granulomatous lesions in cattle and their importance in the epidemiology of bTB. In conclusion, characterization of these isolates to specific species level and further investigation aiming at identification of the source of NTM infections, transmission routes, pathogenicity and their public health significance in the study area is recommended.