Global Burden of Trichostrongylus Infections in Humans: A Systematic Review and Meta-Analysis

Trichostrongylus species are zoonotic gastrointestinal nematodes that occasionally infect humans, particularly in rural areas with close contact to livestock. However, the global prevalence of human trichostrongylosis remains uncertain. This systematic review and meta-analysis aimed to synthesize available prevalence data and describe regional and methodological differences in reported infections. Studies published between 2000 and 2025 reporting the prevalence of Trichostrongylus infections in humans (primarily T. colubriformis, T. axei, and T. orientalis) were searched in six databases (EMBASE, Ovid, PubMed, Scopus, Nursing & Allied Health Premium, and Web of Science) and Google Scholar. Pooled prevalence was estimated using a random-effects model. Subgroup analyses were conducted to assess prevalence by continent, country, population group, and diagnostic method. Thirty-seven studies from 14 countries, comprising 111,408 participants, were included. Most studies were conducted in Asia (23, 62.2%), particularly in Iran (12, 32.4%), and in Africa (12, 32.4%), mainly in Nigeria (5, 13.5%). The global pooled prevalence of Trichostrongylus infection was 1.2%. Prevalence was highest in Africa (1.7%), followed by South America (1.2%), Asia (1.0%), and Europe (0.8%). Subgroup analyses revealed substantial heterogeneity in prevalence across study populations, age groups, and detection methods (p < 0.05). Available evidence suggests that human Trichostrongylus infection remains a localized but persistent zoonotic concern in specific endemic regions, rather than a globally uniform problem. Diagnostic variability, limited regional coverage, and high heterogeneity highlight the need for standardized molecular diagnostics and broader surveillance to accurately define the global epidemiology of trichostrongylosis.