Sero-epidemiology of bovine tuberculosis in dairy cattle in Chattogram, Bangladesh

Objective: Bovine tuberculosis (bTB) is caused by Mycobacterium bovis both in wild and domesticated
animals including cattle, and is a significant public health concern due to its cross-species transmissibility.
We conducted this study on the dairy farms in Chattogram district of Bangladesh to estimate the
seroprevalence and potential risk factors at both animal and farm levels associated with the occurrence of
bTB. We targeted to illustrate a complete picture of bTB to the farmers, policymakers and dairy practitioners.
Materials and Methods: Based on the highest density of intensive dairy cattle farms, we recruited three
subdistricts namely Double Mooring, Shikolbaha, and Raozan of Chattogram for this cross-sectional study.
We sampled a total of 538 animals from randomly selected 37 farms of the selected subdistricts. We collected
blood samples from the animals for performing ELISA in the laboratory and used a pretested questionnaire
for data collection and epidemiological analysis.
Results: We estimated the overall seroprevalence of bTB was 38.2% and 7.5% at the farm level and animal
level respectively. Random effect logistic regression model estimated the low to moderate stocking density
(OR=19.6, p=0.02) as the significant risk factor of bTB at the farm level whereas, farms own stock (OR= 3.4,
p=<0.01) has been calculated as significant risk factors at individual animal level.
Conclusion: For a dairy-intensified area of any developing country like Bangladesh, a coordinated effort of
both veterinarians and local public health officials is critical for implementing an efficient TB control
program. A comprehensive survey is always recommended for early detection and control of the zoonotic
spillover events of any organisms. Therefore, these research findings will aid in the prevention and control
of bTB in the studied region and will prompt removal and good farm management practices. Overall, this
study will make dairy farmers and policy planners aware of the necessity of continuous surveillance to
eradicate TB from the farm levels in any developing and underdeveloped nations across the world.