The impact of carbapenemase-producing Enterobacteriaceae colonization on infection risk after liver transplantation: a prospective observational cohort study

Objective: To investigate the impact of colonization with carbapenemase-producing Enterobacteriaceae (CPE) on the CPE infection risk after liver transplantation (LT). Methods: Prospective cohort study of all adult patients undergoing LT at our centre over an 8-year period (2010–2017). Individuals were screened for CPE colonization by rectal swabs at inclusion onto the waiting list, immediately before LT and weekly after LT until hospital discharge. Asymptomatic carriers did not receive decolonization, anti-CPE prophylaxis or pre-emptive antibiotic therapy. Participants were followed up for 1 year after LT. Results: We analysed 553 individuals who underwent a first LT, 38 were colonized with CPE at LT and 104 acquired colonization after LT. CPE colonization rates at LT and acquired after LT increased significantly over the study period: incidence rate ratios (IRR) 1.21 (95% CI 1.05–1.39) and 1.17 (95% CI 1.07–1.27), respectively. Overall, 57 patients developed CPE infection within a median of 31 (interquartile range 11–115) days after LT, with an incidence of 3.05 cases per 10 000 LT-recipient-days and a non-significant increase over the study period (IRR 1.11, 95% CI 0.98–1.26). In multivariable analysis, CPE colonization at LT (hazard ratio (HR) 18.50, 95% CI 6.76–50.54) and CPE colonization acquired after LT (HR 16.89, 95% CI 6.95–41.00) were the strongest risk factors for CPE infection, along with combined transplant (HR 2.60, 95% CI 1.20–5.59), higher Model for End-Stage Liver Disease at the time of LT (HR 1.03, 95% CI 1.00–1.07), prolonged mechanical ventilation (HR 2.63, 95% CI 1.48–4.67), re-intervention (HR 2.16, 95% CI 1.21–3.84) and rejection (HR 2.81, 95% CI 1.52–5.21). Conclusions: CPE colonization at LT or acquired after LT were the strongest predictors of CPE infection. Prevention strategies focused on LT candidates and recipients colonized with CPE should be investigated