Background: Allogeneic bone marrow transplant (BMT) as well as liver, heart, and lung transplant patients have high reported incidence rates of Clostridioides difficile infection (CDI). The prevalence and incidence of asymptomatic colonization with Clostridioides difficile (ACCD) in this group is not known. Methods: ACCD was defined as the presence of C. difficile on screening cultures without positive clinical testing for CDI ±1 week from the date of sampling. Patients undergoing BMT as well as liver, heart, and lung transplants at MUSC between October 2017 and October 2019 were cultured for C. difficile at admission for transplant then once weekly during inpatient admissions and at each outpatient follow-up for 90 days after transplantation. Testing for CDI occurred at the discretion of treating physicians and was done by PCR. Transient ACCD was defined as a positive culture from samples collected <7 days apart, and persistent ACCD was defined as having 2 or more positive cultures collected a minimum of 7 days apart. Results: The baseline prevalences of ACCD were 1 of 5 (20%), 0 of 2 (0%), 1 of 40 (3%), and 2 of 16(13%) for lung, heart, liver and BMT patients, respectively. Of 63 patients, 3 had a pretransplant history of CDI, 2 of whom had baseline ACCD. Incident ACCD occurred in 23 of 63 patients (37%) (Table 1). Overall, ACCD was observed in 30 of 63 patients (48%). Of the 30 patients with ACCD, 14 displayed persistent asymptomatic colonization, whereas 16 displayed transient asymptomatic colonization. Also, 5 patients in the cohort were diagnosed with CDI after transplantation, of whom 3 had ACCD prior to or following CDI. Conclusions: The baseline prevalence of C. difficile colonization in transplant patients (6.3%) was not substantially greater than those observed in recent studies of hospitalized inpatients, but the incidence of new colonization events (37%) was high in this patient population with numerous pretransplant risk factors for CDI.

Funding: None

Disclosures: None