Bovine brucellosis sero-prevalence trend during 2011-14 and 2015-18 in Indian sub-continent.

Brucellosis, a significant zoonotic disease impacting livestock and human health poses substantial economic and public health challenges in endemic regions. This study analyses and compares the sero-prevalence of bovine brucellosis across 14 states in India over two distinct periods: 2011-14 and 2015-18. A stratified random sampling approach and a protein G-based indirect Enzyme Linked Immunosorbent Assay (iELISA) were employed to evaluate 6408 bovine serum samples during 2015-18 (cattle- 4495; buffaloes- 1913) and results were compared to published data of 2011-14. Chi-square test and analysis of variance (ANOVA) were carried out to know the significance among the states and also between the two time periods. Bovine brucellosis sero-prevalence across Indian states showed a significant decline from 2011 to 14 to 2015-18. In cattle, sero-prevalence reduced from 9.60 to 1.76% (p < 0.0001) with notable reductions in seven states (Gujarat, Madhya Pradesh, Karnataka, Kerala, Maharashtra, Tamil Nadu, and Rajasthan). Except in the state of Punjab, highest sero-prevalence was noted despite a significant decrease (p = 0.002). Whereas, in buffaloes, prevalence declined from 5.35 to 2.67% (p < 0.0001), with significant reduction in two out of ten states tested with modest decreases in other states. The study revealed that only 2 out of 10 states showed reduced brucellosis sero-prevalence in buffaloes indicating the need for aggressive control efforts and continued investment in surveillance, vaccination, and public health education.