Melioidosis Seroprevalence in Animals: Systematic Review and Meta-Analysis

Background: Burkholderia pseudomallei, the causative agent of melioidosis, infects diverse animal species and reflects environmental contamination. However, the global seroprevalence of B. pseudomallei in animals remains incompletely characterized. Methods: A systematic review and meta-analysis were conducted according to PRISMA guidelines and registered in PROSPERO (CRD420261306404). PubMed, Embase, and Scopus were searched for observational studies reporting seroprevalence of B. pseudomallei in animals. Random-effects meta-analysis was performed to estimate the pooled prevalence with 95% confidence intervals (CIs). Subgroup analyses were conducted by animal group, geographic region, diagnostic method, and indirect hemagglutination assay (IHA) cut-off value. Risk of bias was assessed using the Joanna Briggs Institute checklist. Results: Twenty studies involving 78,914 animals were included. The pooled seroprevalence of B. pseudomallei was 11% (95% CI: 6-19%), with substantial heterogeneity (I² = 98.1%, p < 0.0001). Wildlife showed the highest prevalence (16%; 95% CI: 10-25%), followed by livestock (11%; 95% CI: 6-19%). Significant geographic variation was observed (p < 0.0001), with higher prevalence reported in North America (18%) and Southeast Asia (10%). Seroprevalence estimates varied according to diagnostic method and IHA cut-off values. Sensitivity analyses yielded similar pooled prevalence estimates after exclusion of small studies, supporting the stability of the overall findings despite persistent heterogeneity. Conclusions: Exposure to B. pseudomallei is widespread among animal populations and influenced by geographic and methodological factors. Standardized diagnostic approaches and expanded animal surveillance are needed to improve understanding of melioidosis epidemiology within a One Health framework.