Epidemiology and risk factors for nosocomial bloodstream infections in solid organ transplants over a 10-year period

Background: Bloodstream infections (BSIs) are a leading cause of morbidity and mortality in solid organ transplantation (SOT). We sought to determine the types of nosocomial BSIs and risk factors for them in SOT.

Methods: Prospectively collected databases of all SOT and nosocomial BSIs occurring at our institution for a 10-year period were reviewed.

Results: From 2003-2012, we observed 157 nosocomial BSI episodes in 2257 SOTs, the majority of which were caused by staphylococci and enterococci (67.5%). The most common sources of BSI were central line, organ space, respiratory, and gastrointestinal. Kidney transplant patients had the lowest risk of acquiring a BSI compared with other SOT types. Lung transplant patients were at increased risk of methicillin-resistant Staphylococcus aureus BSI and heart transplant patients were at increased risk of a Candida albicans BSI, when compared to other organ transplant types. When coagulase-negative Staphylococcus (CoNS) or C. albicans was isolated, the central line was most often the source. The implementation of central-line bundles during the study period correlated temporally with a decreased rate of CoNS BSI. Over the 10-year period, vancomycin-resistant enterococci became the most common enterococcal BSI. Donor-positive cytomegalovirus status was associated with an increased risk of BSI, when compared to donor-negative patients.

Conclusions: This study demonstrates the common sources, risk factors, and causative organisms of BSI, which can guide empiric antibiotic choices, and highlights areas where preventative interventions could be targeted to prevent nosocomial BSI in SOT.