Background: Blastocystis is a widely distributed, unicellular, anaerobic intestinal protozoan parasite. Blastocystis hominis accused to be possible cause of irritable bowel syndrome, inflammatory bowel diseases, and chronic diarrhea. It has many morphologic forms and is transmitted via fecal-oral route through ingestion of cysts. Laboratory diagnosis of Blastocystis infection is usually via microscopic examination of freshly stained or chemically preserved stool samples but it lacking the sensitivity. The current study is concerned with evaluation of sensitivity and specificity of culture test in comparison to other ordinary staining methods (trichrome, MZN and iodine) for diagnosis of Blastocystis hominis.
Subjects and Methods: Stool samples were collected from seventy two cases, complaining of different gastrointestinal troubles and attending to different Outpatient Clinics of Zagazig Hospitals. All samples were examined microscopically by wet mount, saline, iodine then preserved for staining by Modified Ziehl-Neelsen (MZN) and trichrome stain and were cultured on Boeck and Drbohlav Locke egg serum medium (LE), then examined by light microscope with objectives x10, x40 and x100.
Results: Blastocystis hominis infection was common in younger aged males (14-35years). Conventional methods for diagnosis of Blastocystis e.g simple saline, iodine stained smears, MZN and trichrome stain are simple, specific, non-invasive methods but with low sensitivity. Stool culture was more accurate and sensitive for detection of Blastocystis than direct microscopy.
Conclusions: LE medium culture offers better sensitivity than other ordinary methods for detecting B. hominis infection in stool samples. It is suitable for use in large hospitals or public health laboratories.