Introduction: Intestinal parasites are common in children in poor countries around the world, and are the cause of serious health problems. Objective: To evaluate the prevalence of intestinal parasites in schoolchildren in Santarém, and associated socio-environmental risk factors. Methods: Questionnaires were applied to parents, and fecal exams were performed by direct method and sedimentation. Results: The parasites that prevailed were Entamoeba coli (20.4%) and Ascaris lumbricoides (9.0%). The family income is an important factor related to parasitic infections (χ 2 =21.000/p=0.001). Other factors such as water treatment (χ 2 =20.15/p=0.002), health infrastructure (χ 2 =25.40/p=0.001), and hygiene practices such as hand washing (χ 2 =11.54/p=0.003) were statistically significant for the presence of intestinal parasites too, some on a lesser scale.
Conclusion:The results showed that Entamoeba coli and Ascaris lumbricoides are the prevalent parasites. The family income, water quality, and sanitary infrastructure are the main risk factors for parasitic infections.