Global prevalence and public health impact of intestinal parasitic infections in children under five: a systematic review and meta-analysis

BACKGROUND: Intestinal parasitic infections (IPIs) remain a significant public health concern worldwide, particularly affecting children under five years old. These infections contribute to malnutrition, impaired growth, diarrhea, and increased morbidity and mortality, disproportionately impacting low- and middle-income countries. This systematic review and meta-analysis aims to estimate the global prevalence of IPIs in children under five and examine the influence of socioeconomic, environmental, and diagnostic factors. METHODS: A systematic literature search was conducted based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines across multiple databases (PubMed, Web of Science, Scopus, ScienceDirect, and Google Scholar) for cross-sectional studies reporting the prevalence of IPIs in children under five years old, up to November 2025. The pooled prevalence was estimated using a random-effects meta-analysis, and subgroup analyses were performed by region, human development index (HDI), income level, climate, diagnostic method, and parasite species. Methodological quality was assessed using an adapted Newcastle-Ottawa Scale. RESULTS: Forty-one studies, involving a total of 15,109 children under five, met the inclusion criteria. The study population was drawn from multiple regions worldwide. The overall pooled prevalence of IPIs in children under five was 31.60% (95% CI: 26.04-37.44). Prevalence was highest in lower-middle-income countries (37.45%) and low-HDI regions (35.17%), and lowest in high-income countries (6.25%) and very high-HDI regions (19.41%). South Asia (35.47%) and Eastern sub-Saharan Africa (35.24%) were identified as major hotspots. Helminth infections were most commonly caused by Ascaris lumbricoides (11.93%), while Giardia lamblia (10.37%) was the predominant protozoan. Studies using more sensitive diagnostic methods reported substantially higher prevalence. Environmental factors such as tropical savanna climates, moderate rainfall, and high humidity were associated with increased infection rates. Gender differences in prevalence were negligible. CONCLUSIONS: IPIs continue to pose a substantial global health burden on children under five, with socioeconomic and environmental disparities strongly influencing prevalence. The findings highlight the need for targeted public health interventions, including deworming programs, improved sanitation, and clinical surveillance, particularly in high-burden regions. Enhanced diagnostic strategies are essential to accurately capture infection rates and guide effective prevention and treatment efforts.