Abstract
BACKGROUND: Mycobacterium bovis, the causative agent of bovine tuberculosis, is a zoonotic pathogen capable of infecting cattle and humans. Human contraction of bovine tuberculosis, particularly pulmonary infection, remains a significant public health concern. The differentiation between Mycobacterium bovis and Mycobacterium tuberculosis is challenging due to limitations in conventional diagnostic methods, leading to an underestimated burden of M. bovis in human population. This study focuses on the prevalence of M. bovis in cases of pulmonary tuberculosis in a tertiary care teaching hospital located in Karamsad, Anand, a rural district of Gujarat.
METHODS: In this cross-sectional study, 1,000 sputum samples from patients clinically suspected of having pulmonary tuberculosis were collected at the Department of Respiratory Medicine from November 2017 to June 2018. All samples underwent Ziehl-Neelsen staining for Acid Fast Bacilli detection, followed by molecular testing using primers targeting the HupB gene (a histone-like protein), to differentiate between M. tuberculosis and M. bovis. Results: Of the 1,000 sputum samples, 100 (10%) tested positive for Acid Fast Bacilli. Molecular analysis revealed that 90% of these positive samples were M. tuberculosis. Among the remaining samples, 4% were positive for M. bovis, and 6% indicated a mixed infection with both M. tuberculosis and M. bovis. Conclusion: The study found the prevalence of M. bovis in 10% cases of pulmonary tuberculosis in the Anand district of Gujarat. The findings highlight the limitations of conventional diagnostic methods in identifying M. bovis infections and demonstrate the efficacy of molecular techniques, explicitly targeting the HupB gene, for accurate detection and differentiation of M. tuberculosis and M. bovis. The evidence of coinfection in 6% patients further emphasizes the complexity of tuberculosis diagnosis in endemic areas.