Transboundary Animal Diseases Associated With Cross-Border Camel Movement. A Systematic Review and Meta-Analysis

Transboundary animal diseases (TADs) are contagious diseases that significantly impact livestock health, public health and economic stability. In regions with frequent cross-border trade and transhumance involving camels, particularly the Middle East and Africa, TADs pose a heightened One Health risk due to their zoonotic potential and capacity to spread rapidly across national boundaries. This review synthesises current knowledge on TADs, with a focus on zoonotic pathogens affecting camels involved in cross-border movement, identifies geographical trends, and highlights research gaps to inform surveillance and control strategies. We conducted a comprehensive search across Ovid Medline, PubMed, Web of Science, Scopus, and Cochrane databases without time restrictions. Eligible studies were assessed for study quality and risk of bias using the Joanna Briggs Institute Critical Appraisal Checklist tools. Pooled prevalence estimates for TADs were calculated using random-effects models, with subgroup and meta-regression analyses to explore heterogeneity. Forty-five eligible articles were included, identifying 15 zoonotic TADs. Middle East respiratory syndrome (MERS) (34%), Rift Valley fever (RVF) (15%). The cross-border movements of camels contribute to the transnational spread of TADs, exacerbated by informal trade routes and nomadic pastoralism in arid regions. Our findings highlight the urgent need for harmonised surveillance and control strategies to mitigate the spread of zoonotic TADs through camel trade. Therefore, strengthening cross-border surveillance, harmonising diagnostic protocols, and integrating animal-human-environment data within a One Health framework is critical to mitigating zoonotic disease threats in these regions.