Cost containment of formalin-preserved stool specimens for ova and parasites from outpatients.

Three individual formalinized stool specimens from each of 123 patients were pooled and examined for ova and parasites. Results obtained from the pooled specimens were compared with those obtained with the three individual specimens used to make the pooled specimens. Of 123 sets examined, 92 were negative and 31 were positive for ova and parasites. The pooled specimens were positive and all individual specimens were negative eight times, whereas the pooled specimens were negative and the individual specimens were positive twice. The data indicated that the pooled system is a useful and economical method of screening for ova and parasites.