Seroprevalence and associated epidemiological drivers of glanders in horses: a systematic review and meta-analysis (2002-2026).

Abstract

Glanders (malleus), a highly contagious zoonotic disease caused by Burkholderia mallei, remains an important transboundary disease of equids despite extensive control efforts in many countries. However, its epidemiological patterns and associated drivers have not been comprehensively synthesized. This study aimed to estimate the seroprevalence of glanders in horses and identify key epidemiological drivers based on studies published up to April 27, 2026. Following PRISMA 2020 guidelines, systematic searches were conducted in PubMed, Scopus, Web of Science, ScienceDirect, Cochrane Library, ProQuest, and Google Scholar. Study quality was assessed using the Joanna Briggs Institute checklist for prevalence studies. Random-effects meta-analyses, subgroup analyses, meta-regression, and publication bias assessments were performed using RStudio version 4.4.3. Twenty studies met the inclusion criteria. The pooled seroprevalence of glanders in horses was estimated at 3.02% (95% CI: 0.82-6.36). Glanders was reported predominantly in South Asia and South America, with the highest prevalence estimates observed in French Guiana and Iraq. ELISA was the most frequently employed diagnostic method. Higher prevalence estimates were observed during the rainy season and in animals with poor body condition. Meta-regression analysis revealed a temporally increasing trend in glanders seroprevalence in horses. Strengthened surveillance, harmonised diagnostics, and targeted control strategies are essential to reduce the disease burden and mitigate further re-emergence.