The prevalence of emerging human intestinal protozoan pathogens in immune-competent adults was
not clearly determined in Egypt. This study assessed the prevalence of Cyclospora cayetanensis and
Cystoisospora belli and their associated risk factors in Minia Governorate, Egypt. Fecal samples were
collected from 190 immunocompetent patients suffering from diarrhea with or without other gastrointestinal
manifestations, from June 2018 to February 2019. Questionnaires for demographic and clinical
data were filled out for each patient. Fecal samples were examined macroscopically and microscopically
followed by modified Ziehl Neelsen stain to identify oocysts Cyclospora cayetanensis and
Cystoisospora belli. 113 patients (59.5% with 95% CI, 52.5-66.5) out of 190 patients were infected
with Cryptosporidium spp., Blastocystis spp., Entamoeba histolytica/dispar, Giardia intestinalis, Cyclospora
cayetanensis, and Cystoisospora belli. Co-infection was detected in 22 cases (11.6%) and
single parasitic infection was detected in 91cases (47.9%). Cyclospora cayetanensis was reported in 19
cases (10%) While, Cystoisospora belli was detected in 3 cases (1.7%). Cyclospora cayetanensis and
Cystoisospora belli infections were significantly associated watery diarrhea and higher consumption of
unwashed fruit or vegetable with no role for animal contact in their transmission. The study result implicated
that C. cayetanensis is an important cause of adult diarrhea.