Worldwide Seroprevalence and Risk Factors of Toxoplasma gondii Exposure Among Students: A Systematic Review and Meta-Analysis

Abstract

Background Toxoplasma gondii, a zoonotic protozoan parasite, affects approximately one-third of the global population and is associated with congenital and neurological complications. While seroprevalence has been extensively studied in high-risk groups such as pregnant women, data on students, a population spanning childhood to young adulthood, are fragmented. We aimed to systematically assess the global seroprevalence and risk factors of T. gondii exposure among students to inform public health strategies for this demographic. Methods We conducted a systematic review and meta-analysis following PRISMA guidelines, with the protocol submitted to PROSPERO (CRD42025637197). We searched PubMed, Scopus and Web of Science from database inception to January 2025 for cross-sectional and observational studies reporting T. gondii seroprevalence in students (primary, secondary, undergraduate or postgraduate) using serological methods, with no language restrictions. Random-effects models were used to estimate pooled seroprevalence and risk factors, with heterogeneity assessed via I2 statistics and meta-regression. Bias was evaluated using Begg's and Egger's tests. Results From 50 studies involving 32,054 students across 24 countries, the pooled global seroprevalence of T. gondii was 14.0 (95 CI 11.7-16.6; I2 = 98.33). Seroprevalence varied by educational level: 28.5 (95 CI 20.6-37.7) in primary school students, 19.3 (95 CI 14.1-25.8) in secondary school students, 19.4 (95 CI 14.5-25.5) in undergraduates and 2.5 (95 CI 0.2-27.8) in postgraduates (based on one study). Significant risk factors included contact with cats (RR 1.888, p < 0.001), soil exposure (RR 1.940, p < 0.001) and consumption of undercooked meat (RR 1.450, p = 0.003). Meta-regression identified diagnostic methods and geographic coordinates as key sources of heterogeneity (explaining 35-73). High between-study heterogeneity was observed across most analyses. Conclusions Health education programs in schools, promoting hand hygiene, safe food practices and responsible pet care, could reduce T. gondii exposure among students, particularly in high-prevalence regions. Further research is needed to explore the cognitive and behavioural impacts of infection in this population and to better characterize regional sources of heterogeneity.