Bovine Tuberculosis in Cattle Slaughtered at Abattoir in Ethiopia and Workforce Awareness of Zoonotic Risk

Abstract Background Bovine tuberculosis (bTB) is endemic and of zoonotic importance in Ethiopia. Despite this, there is limited recent information on the prevalence of bTB in cattle slaughtered at abattoirs. This study reports the prevalence of bTB in cattle slaughtered at the Addis Ababa municipality abattoir and details an assessment of practice and the awareness of occupational workers to zoonoses. Methods A cross-sectional study was conducted at the Addis Ababa municipality abattoir from May 2021 to July 2022. A total of 502 cattle slaughtered at the municipality abattoir (260 in the day shift and 242 in the night shift) were included in the study. Data collection and laboratory investigations included postmortem examination, culture and bacteriological examination, molecular characterization of positive isolates using region of difference (RD4) deletion typing and spoligotyping. Knowledge of zoonotic infection risk and practices were investigated through a questionnaire administered to 58 abattoir workers and 58 butchers. Results Based on postmortem examination, bTB suspected lesion was identified in 4.58% of cattle and it was significantly associated with, age, breed and body condition of the animals. Detection of tuberculosis lesions was higher during the night shift of the slaughter program. The gross lesions were predominately found in the lung and associated lymph nodes (60.87%). Of the 23 bTB suspected tuberculous lesions, 11 (47.83%) tissue samples were culture positive, and four isolates were RD4 positive, identifying M. bovis. Spoligotyping patterns were also effectively detected in four isolates. The observed spoligotype patterns were two SB1477 strains, and SB1176 and SB0133 strains. In the questionnaire survey, 79.31% of abattoir workers were aware of bTB, however, 93.10% of butchers did not know of bTB and understood less about preventing cross-infection. Conclusion Bovine tuberculosis is still evident in cattle reaching the abattoir in Addis Ababa. Higher detection of tuberculous lesions during the night suggests a need for improved meat inspections during the night shift to reduce the public health risk of bTB zoonosis.