The global prevalence of Giardia infection in horses: A systematic review and meta-analysis

Giardia duodenalis as a common zoonotic parasite is a public health problem infecting humans and a wide range of animals, including horses. This systematic review and meta-analysis was conducted to estimate the global pooled prevalence of Giardia infection in horses. Literature searches were conducted using databases including Scopus, ScienceDirect, PubMed, Web of Science and ProQuest to December 2023. A random-effect model was performed to calculate the pooled prevalence and corresponding 95% confidence interval (CI) according to the degree of heterogeneity in the included studies. Of 2661 articles, approximately 27 articles were eligible for inclusion in the meta-analysis. The pooled prevalence of giardiasis in horses using the random effect method was 8.93% (95% CI = 5.98% to 12.42%). There were significant differences between the giardiasis prevalence in different continent, countries and ages of horses. The highest and lowest prevalence of giardiasis was found in Europe (12.24%) and Africa (0 %), respectively. The prevalence of Giardia was significantly higher in horses <3 years of ages. Based on the diagnostic method, the highest and lowest incidence of horse Giardia infection was detected by immunological assays (9.24%) and molecular methods (7.87%), respectively. The result of our study showed that assemblage B is the most common genotype in horses followed by assemblage A and E. Due to the widespread use of horses on farms or for recreational riding, data on the source of infection, prevalence, transmission mechanisms, and genotype are crucial for the establishment of control and prevention strategies.