Global prevalence and risk factors of bovine tuberculosis in cattle: a systematic review and meta-analysis.

Abstract

INTRODUCTION: Bovine tuberculosis (bTB), caused by, is a chronic zoonotic disease of major global importance, particularly in low- and middle-income countries where surveillance and control remain inadequate. OBJECTIVES: This systematic review and meta-analysis aimed to estimate the global prevalence of bTB, identify key risk factors, and evaluate diagnostic approaches to support evidence-based control strategies within a One Health framework. METHODS: A systematic search following PRISMA 2020 guidelines was conducted across eight electronic databases (PubMed, Web of Science, Scopus, ScienceDirect, Google Scholar, CAB Abstracts, SpringerLink, and AJOL) for studies published between 1990 and October 2025. A total of 7,775 records were identified, of which 98 studies met the inclusion criteria and were included in the quantitative synthesis. RESULTS: The pooled global prevalence of bTB was estimated at 3.98% (95% CI, 3.94-4.03) and an overall herd's estimate was 18.48% (95% CI, 17.47-19.49). Meta-analysis revealed a significantly lower odds of infection at the animal level compared to herd level (OR&#x202f;=&#x202f;0.23; 95% CI: 0.15-0.37;&#x202f;<&#x202f;0.00001; I&#x202f;=&#x202f;94%), indicating higher cumulative detection in herds. Subgroup analysis showed that Africa contributed the largest proportion of reported cases (61.22%), followed by Asia (30.61%), while other continents had marginal contributions. At regional level, Eastern Africa accounted for 41.84% of included studies, with Ethiopia representing the highest country-specific contribution (34.69%). Age-stratified analysis indicated higher prevalence in older cattle (&#x2265;5&#x202f;years: 21.80%; 95% CI: 14.19-30.71) compared to younger animals (<5&#x202f;years: 12.90%; 95% CI: 6.55-19.98), with borderline statistical significance (OR&#x202f;=&#x202f;0.81; 95% CI: 0.66-1.00;&#x202f;=&#x202f;0.05). Among diagnostic methods, tuberculin-based skin tests were most frequently used (42.86%), followed by molecular techniques (23.47%). Sample type analysis showed the highest detection rates in skin samples (41.84%), followed by blood (28.57%) and milk (14.29%). Breed-specific analysis revealed higher prevalence in Holstein cattle (30.08%) compared to indigenous zebus (9.08%), suggesting increased susceptibility in improved breeds. Despite generally symmetrical funnel plots indicating low publication bias, substantial heterogeneity was observed across analyses (I&#x202f;>&#x202f;75%), reflecting methodological and regional variability. CONCLUSION: Bovine tuberculosis remains a persistent and unevenly distributed zoonotic disease, with a disproportionate burden in Africa and Asia. The higher detection at herd level, significant influence of age and breed, and variability in diagnostic methods underscore the need for harmonized surveillance systems, improved diagnostic standardization, and targeted control strategies.