Epidemiology and Risk Factors of Bovine Tuberculosis

Bovine tuberculosis (bTB) is a chronic infectious disease of cattle caused by Mycobacterium bovis. It persists in both extensive and intensive production systems across Africa, Asia, Europe and the Americas, with eradication achieved in some high-income regions but ongoing endemicity in many low- and middle-income countries. Wildlife reservoirs and mobile pastoral herds maintain infection cycles at the wildlife-livestock interface, while movement of animals for trade and transhumance amplifies transmission. Zoonotic spill-over to humans, primarily via unpasteurised milk, raw meat or occupational exposure, underscores its public health importance. Epidemiological studies have linked herd size and density, herd management practices, contact with wildlife maintenance hosts and animal movement to bTB prevalence. At the individual level, risk increases with age, poor body condition and certain cattle breeds. Control strategies combine surveillance, diagnostic testing and tailored management interventions that reflect local socioeconomic realities.

Research from Nature Portfolio

Recent studies in intensive dairy systems have compared traditional test-and-cull with a test-and-segregation approach under resource constraints. Both methods achieved complete elimination of detectable bTB after multiple testing rounds, but test-and-segregation proved roughly half as expensive as culling, mainly by reducing animal losses and culling overheads. Crucially, the adoption of more sensitive diagnostic thresholds in later testing rounds enhanced detection of low-grade infections, demonstrating that optimised testing protocols are vital for sustainable control in high-prevalence herds where outright culling may be economically or socially infeasible.

Epidemiology and Risk Factors of Bovine Tuberculosis publication trend

The graph below shows the total number of articles in epidemiology and risk factors of bovine tuberculosis across all publications each year (not limited to Nature Index journals).

Technical terms

Seroprevalence: Proportion of a population with detectable antibodies against a pathogen, indicating past or current exposure.

Test-and-cull: Disease control strategy involving regular diagnostic testing and removal of positive animals to interrupt transmission.

Test-and-segregation: Control approach in which positive animals are isolated rather than destroyed, aiming to limit spread while preserving stock.

Comparative cervical test (CCT): Intradermal skin test comparing bovine and avian tuberculin reactions to diagnose bTB in cattle.

Zoonotic transmission: Transfer of pathogens from animals to humans, exemplified by human infection with M. bovis from cattle.

References

1. Assessing the feasibility of test-and-cull and test-and-segregation approaches for the control of high-prevalence bovine tuberculosis in Ethiopian intensive dairy farms. Scientific Reports (2024).
2. Seroprevalence and risk factors associated with bovine tuberculosis in cattle in Eastern Bhutan. PLOS Neglected Tropical Diseases (2024).
3. Zoonotic tuberculosis in a high bovine tuberculosis burden area of Ethiopia. Frontiers in Public Health (2023).
4. Risk factors of bovine tuberculosis in cattle in rural livestock production systems of Ethiopia. Preventive Veterinary Medicine (2009).