Dr.Israa Mohammad Abd AL-Khaliq Al-Hasan, B.Sc. Baghdad University ,College of Science 2001, M.Sc. Baghdad University , College of Science 2005, Ph.D. Al mustansiryiah University ,College of Science 2015, Actually work as an Assistant Professor in AL-Kindy college of medicine/ Department of Microbiology.

The present study included (5892) stool sample , which were collected from patients at different ages (1-70 year) of both sexes, complained with abdominal pain, cramp, flatulence and diarrhea. Samples were collected during the period from September (2013) till September (2014), included four hospitals in Baghdad (Baghdad Medical City , AL-Imam Ali Hospital, AL-Karaama Hospital and AL-Yarmouk Teaching Hospital ) . To detect of the infection prevalence of Blastocystis hominis , the results of epidemiological study showed that the total number infected with this parasite was (1420) positive sample with percentage of (24.10%) , Percentages of infected cases with parasite in the four hospitals (Baghdad medical city, AL-Imam Ali Hospital , AL-Karaama Hospital and AL-Yarmouk Teaching Hospital), were (51.41%,18.66%,17.61%,and 12.32%) respectively . Males showed higher number and percentage of infection, (750 ) case with percentage of (52.82%), while females were (670) case with percentage of (47.18%) , no statistical significant differences was detected.