[Morphology of Blastocystis hominis in feces and evaluation of parasitological methods]

A study of the morphology of Blastocystis hominis in stool in ninety-four cases humans is described as central body, ameba and granular form were found as previously described. In addition a "Globulose" form as a variation of granular form is first described. The central body form (96.8%) was the most abundant form. Three parasitological methods as direct microscopical examination sample with saline solution 0.85%, lugol, Sudan III, stained with Quensel, Iron hematoxylin and culture are evaluated to detection the Blastocystis hominis forms. Our results show that the direct microscopical examination (saline solution 0.85%, lugol, Sudan III, stained with Quensel) is the most sensitive and specific method than culture. The identification of Blastocystis hominis in stool difficult due to the diversity of shapes and size, which generate confusion with other intestinal protozoa and host cells.