Diarrheal Morbidity in Patients Undergoing Hematopoietic Cell Transplantation – the Diagnostic Yield of Stool Cultures

Diarrhea affects a significant proportion of patients undergoing hematopoietic cell transplantation (HCT). In this single center retrospective study, we explored the diagnostic yield of stool cultures for enteric pathogens among patients undergoing HCT. Between May 2007 and April 2020, a total of 1072 individuals underwent autologous (n=603) and allogeneic (n=469) HCT. Overall, 947 stool culture samples were obtained from 561 (52%) patients with diarrheal illness during hospitalization for HCT. Most (99%) samples were obtained beyond 3 days of admission and mainly (77%) during neutropenia. Overall, only four (autologous HCT, n=3; allogeneic HCT, n=1) patients were diagnosed with positive stool culture (0.42%) and in all cases, Campylobacter spp. was the pathogen identified. All isolates grew from the first stool culture obtained. The number of stool cultures needed-to-test to diagnose one case of bacterial infection was 237. The cost of diagnosing one case of bacterial infectious diarrhea was 8,770 US dollars. The median time from admission to positive stool culture sample was 12 (range, 7 to 13) days. Patients with a positive stool culture did not have discerning clinical or laboratory characteristics. In conclusion, according to our experience, the yield of stool cultures for enteropathogens in patients undergoing HCT is extremely low and thus should be avoided in most cases.