Detection of Intestinal and Zoonotic Parasites and Acanthamoeba Species in Household Soils and Leafy Green Vegetables in Alto Paraná, Paraguay

In tropical and subtropical settings, soil-associated parasites depend on environmental conditions for persistence and transmission. An exploratory survey of soil parasites and the presence and diversity of Acanthamoeba was conducted in peri-urban Minga Guazú and rural Itakyry to establish baseline data and generate hypotheses for future, adequately powered environmental studies. A total of 136 soil samples from entry, patio, back patio, and latrine sites across 27 locations were tested using multi-parallel quantitative polymerase chain reaction for soil-transmitted helminth and protozoan DNA. Parasites and Acanthamoeba were detected in 88.9% (24/27) of locations, and 44.4% (12/27) exhibited polyparasitism. In Minga Guazú, 95.2% (20/21) of houses tested positive for Acanthamoeba, compared with 50% (3/6) in Itakyry; detection of Acanthamoeba was higher in Minga Guazú (odds ratio: 20.0; 95% CI: 1.53-260.8; P = 0.0248). In Minga Guazú, parasite species richness was higher near latrines than back patios, approaching significance (mean: 0.850 versus 0.500; P = 0.0577). Consistent with observed parasite presence, leafy green vegetables collected from local food stands had a high prevalence of parasites via microscopy (lettuce: 87.6%; parsley: 94.6%; watercress: 100%). In Itakyry, a child infected with Bertiella mucronata was also identified, highlighting emerging zoonotic risks.