Yield of stool cultures, ova and parasite tests, and Clostridium difficile determinations in nosocomial diarrheas.

Stool cultures for bacterial pathogens, ova and parasites, and Clostridium difficile are usually ordered for patients with nosocomial diarrhea. In the interest of cost containment we undertook an 18-month retrospective study to assess the cost/benefit of performing each of these three tests. During the study period nosocomial diarrhea developed in 118 patients. Of 452 bacterial stool cultures ordered, only one was positive for Campylobacter jejuni and none for ova and parasites. However, of 126 cultures examined for C. difficile, 47 showed positive results. We conclude that bacterial stool culture and ova and parasite identification are not indicated for patients with nosocomial diarrhea. Elimination of these unnecessary stool tests (bacterial/ova and parasite) would have saved the hospital approximately +7530 in the 18-month study period.