Blastocystis species (spp.) is a large unicellular intestinal protozoan parasite that has a worldwide distribution. It has unclear pathogenicity and is linked to many clinical disorders. The study purpose was to determine the prevalence of Blastocystis spp. molecularly in a cohort of symptomatic and asymptomatic individuals and to assess the association of Blastocystis spp. with the patient characteristics as possible predictors of the occurrence of Blastocystis spp. Fecal specimens were collected from 139 Egyptians of both sexes, aged from 5 months to 74 years. All fecal specimens were examined coproscopically for detection of gut parasites and cultured on Modified Jones’ medium for detection of Blastocystis spp. Molecular assay using nest...