Pooled prevalence and associated study-level factors of Echinococcus metacestode infection in ruminants in China: A...

Ruminant echinococcosis represents an important livestock-associated component of Echinococcus transmission in China, but national evidence on host-specific prevalence and associated study-level factors remains fragmented. This systematic review and meta-analysis estimated the pooled prevalence of Echinococcus metacestode infection in Chinese small ruminants and bovines and identified significant associated study-level factors. Six databases were searched from inception to April 10, 2026, following PRISMA guidelines. Cross-sectional studies reporting both examined and positive animals were included, and pooled estimates were calculated using random-effects models, subgroup analyses, and meta-regression. A total of 279 studies were included. The pooled prevalence was 24.46% (95% CI: 21.21-27.47) in small ruminants and 21.00% (95% CI: 17.47-24.77) in bovines. In both host groups, significantly higher prevalence was associated with E. granulosus infection, high-altitude areas, particularly > 4000 m, lower-temperature regions, and farm-derived samples. Significant temporal declines were also observed in both small ruminants and bovines, especially after 2012. In small ruminants, additional significant factors included older age, especially animals > 6 years, northwestern China. In bovines, host species was the main host-specific significant factor, with yaks showing the highest prevalence and dairy cattle the lowest. Although not statistically significant, sheep showed a higher prevalence than goats, and higher numerical estimates were also observed in grazing animals, autumn samples, and areas with annual rainfall < 400 mm. These findings support targeted surveillance of high-burden host groups and ecological settings and highlight the need for integrated ruminant echinococcosis control under a One Health framework.