Increasing the Efficiency of Spontaneous Sedimentation for the Diagnosis of Intestinal Protozoa.

The aim of this study was to evaluate the association between a longer sedimentation time, the reading of a larger number of slides, and the collection of multiple samples on the efficiency of the spontaneous sedimentation technique. Twenty-two patients with a previous parasitological exam positive for intestinal protozoa were recruited to collect new fecal samples (3 samples per patient) before the beginning of antiparasitic treatment. All collected fecal samples were used for spontaneous sedimentation and centrifuge-flotation techniques. Of these, all 22 patients were positive based on spontaneous sedimentation, and 59.1% (13/22) based on centrifuge flotation. The number of samples and the number of slides analyzed by spontaneous sedimentation influenced the number of positive cases. The modifications applied to the spontaneous sedimentation technique increased its performance in protozoa diagnosis.