Donor-derived infections in organ recipients are infrequent but associated with high morbidity and mortality. Reported frequencies of occult bloodstream infection (BSI) among organ donors range from 5 to 21%. With preemptive therapy in recipients, the risk of transmission from donor BSI is low (0–3%).

A retrospective cohort evaluation was performed including deceased-donor liver transplants in two centers between 2015 and 2020. Cases without donor blood cultures were excluded. Recipients of organs from donors with pathogenic BSI received preemptive antimicrobial therapy directed at the isolated organism for 5–7 days. Survival at 30 and 365 days was compared between recipients from donors with and without occult BSI using chi-square testing.

Among 678 liver transplants with available donor blood cultures, 231 (34%) had positive donor cultures. Of these, saprophytic microbiota organisms were isolated in 100 cases (14.8%). Donor BSI due to pathogenic microorganisms occurred in 131 cases (19%). The 143 microorganisms isolated included 54 (38%) non-fermenting Gram-negative bacilli, 40 (28%) Gram-positive cocci, 36 (25%) Enterobacterales and 13 (9%) Candida spp. Probable transmission to the recipient occurred in 2 cases (2%). Among recipients of donors with pathogenic BSI, 85% and 77% were alive at 30 and 365 days, respectively. Among those without pathogenic BSI, survival was 84% and 76% at 30 and 365 days. No statistically significant differences were found (p = 0.857 at 30 days; p = 0.8 at 365 days).

Occult donor BSI was frequent in this cohort. With systematic preemptive therapy, donor-to-recipient transmission was rare, and no survival differences at 30 or 365 days were observed between recipients of donors with or without pathogenic BSI.