Application of rejection criteria for stool cultures for bacterial enteric pathogens.

Over 20 months, we prospectively assessed the yield of cultures for Salmonella, Shigella, and Campylobacter spp. from adults and children. In the first 10 months, 53% (567 of 1,097) of specimens from adults were from patients who had been in the hospital for > 3 days. Overall, only 2.6% (29 of 1,097) of specimens contained pathogens, and all were from patients who had been in the hospital for < or = 3 days. Over the second 10 months, specimens from adults in the hospital for > 3 days were not cultured unless special reasons existed. Thirty percent (368 of 1,229) of specimens were rejected. Concurrently, 7.5% (51 of 677) of stool specimens from children were positive. Only one positive specimen came from a child who had been in the hospital for > 3 days. Neither stool consistency nor fecal leukocytes were useful predictors for the presence of an enteric pathogen. We recommend that specimens from both adults and children in the hospital for > 3 days not be cultured unless there are delineated plausible clinical or epidemiological reasons to do so.