Bahman Maleki
* 
, Hadi Khatounaki, Nahid Haghshenas, Reza M Robati, Mostafa Rezaei-Tavirani, Mahmood reza Behravan, Ahmad Abolghazie
Abstract
Human toxocariasis, caused by the larvae of Toxocara canis and Toxocara cati, is a globally prevalent parasitic disease with significant public health implications. Although soil is a primary route of transmission for Toxocara spp., data on soil contamination in Iran remain limited. To address this gap, the present study expands upon a systematic review published in 2018, which analyzed studies conducted between January 2000 and November 2016. This study provides an updated estimate of the prevalence of Toxocara spp. eggs in soil from public areas in Iran, using recent data to guide control strategies. A comprehensive literature search was performed in accordance with PRISMA guidelines, covering studies published between 2000 and April 2025. A random-effects meta-analysis was conducted to pool prevalence rates, and associations with geographic and environmental factors were examined through meta-regression and sensitivity analyses. A total of 28 studies (31 datasets) were included, comprising 6,264 soil samples collected from 25 Iranian provinces. The pooled prevalence of Toxocara spp. eggs was 16% (95% CI: 12–21%), with high heterogeneity (I² = 94.4%, P < 0.001). The high heterogeneity (I² = 94.4%) observed across studies may be attributed to differences in sampling methods, climatic conditions, study quality, and regional variations in stray animal density. Prevalence varied by region and climate, with the highest rates reported in the Central region (23%) and in hot desert climates (20%). No statistically significant effects of sample size, year of publication, or environmental variables were observed. These findings underscore significant environmental contamination by Toxocara spp. eggs throughout Iran. This contamination indicates an ongoing risk of human infection. These results highlight the need for geographically targeted interventions, public education, and integrated One Health strategies to inform health policy and prevent human toxocariasis.