A comparison of the formalin-ether concentration and trichrome-stained smear methods for the recovery and identification of intestinal protozoa.

The detection and identification of intestinal protozoa were compared using the formalin-ether concentration technique and trichrome smears. Using the polyvinyl alcohol (PVA) one-vial collection method, 13,194 outpatient samples were examined by both methods. Twenty-three percent or 3077 specimens were positive for one or more species of intestinal protozoa. Of the pathogenic protozoa identified, 96.3 percent of the trophozoites and 44.2 percent of the cysts were identified only by the trichrome-stained smear. It is recommended that both procedures by included in the examination of fecal sepcimens for protozoa.