The study assessed the risk of intestinal parasitic infections (IPIs) among psychiatric patients in
comparison with controls. A case-control study was conducted on 983 psychiatric patients and
another 983 non-psychiatric controls attending the Psychiatry and Neurology outpatient clinic of
Minia University Hospital, Egypt, during the period from October 2017 to September 2019. A
single fecal sample was collected from each participant and examined by direct saline wet
mount, formol-ether concentration. Modified trichrome and Kinyoun acid-fast staining were
used to confirm suspected cases of protozoa. Our results showed that the rate of IPIs was
significantly higher in psychiatric patients (35%) than in control (10.8%). Multiple IPIs were
found in nine (0.9%) psychiatric patients, but not in controls. Blastocystis hominis was the most
prevalent infection followed by Cryptosporidium parvum. Patients suffering from depression had
the highest prevalence of infection (32.6%).