Prevalence and risk factors of swine tuberculosis in central Ethiopia

Abstract

There is paucity of information in the epidemiology and pathology of tuberculosis in swine though the endemic occurrence of bovine tuberculosis was elucidated in Ethiopia. A cross-sectional study was employed to investigate the epidemiology of Mycobacterium tuberculosis complex and  Mycobacterium avium complex in swine. The study was conducted from September 2016 to December 2017 using single intradermal comparative tuberculin test, gross pathology and histopathology. Tuberculin test was carried out in farmed swine of central Ethiopia while the necropsy at Addis Ababa Abattoirs Enterprise, Ethiopia. Of the total 329 heads of swine tuberculin tested by bovine purified protein derivative antigen, an animal level prevalence of 3% (95% CI: 2-6) and a herd level prevalence of 11% (95% CI: 1-49) were observed at a cut-off value of >2mm. Multivariable logistic regression analysis revealed the protective exposure effect of body condition to tuberculin test positivity in swine (Adjusted OR: 0.06; 95% CI: 0.0-1.1; P: 0.055). Swine were predominantly in close proximity with dairy cattle which is an important risk factor for the transmission of bovine tuberculosis from cattle to swine. Necropsy study of tuberculosis-like lesions in 640 heads of swine revealed an overall lesion prevalence of 4.1 % (95 CI: 2.8-6.0). In conclusion, the present study demonstrated the occurrence of swine tuberculosis in low prevalence in farmed swine and swine slaughtered at
Addis Ababa Abattoirs Enterprise in central Ethiopia. Further in-depth study covering larger sample size and wider areas is warranted so as to identify the prevalent species and their zoonotic importance.

Keywords: Abattoir; Epidemiology; Ethiopia; Pathology; Swine; Tuberculosis