Risk factors for carbapenem-resistant Pseudomonas aeruginosa infection or colonization in a Chinese teaching hospital

Introduction: Carbapenem-resistant Pseudomonas aeruginosa (CRPA) is rapidly emerging as a life-threatening nosocomial infection. In this study, we aimed to identify risk factors, especially antibiotic use and co-carriage with other bacteria for CRPA infection or colonization. Methodology: A retrospective study was conducted in the First Affiliated Hospital of Xi'an Jiaotong University, which involved a cohort of patients with Pseudomonas aeruginosa infection or colonization from January 2014 to June 2016. Univariate analysis and multivariate analysis were performed to estimate the risk factors of CRPA occurrence. Results: Eight hundred and eighty-eight patients were included in the study. More than 50% of the risk factors were associated with CRPA infection or colonization according to univariate analysis (P < 0.05), such as invasive procedures, co-carriage with Gram-negative pathogens, and prior treatment with some antibiotics. However, only prior exposure to carbapenems (OR: 8.005; CI: 4.507-14.217, P < 0.001), the days of carbapenems treatment (OR: 1.190; CI: 1.073-1.272; P < 0.001), and co-carriage with Escherichia coli (OR: 1.824; CI: 1.005-3.310, P = 0.048) were considered independent risk factors by multivariate analysis. A higher mortality was found among patients with CRPA infection or colonization (P < 0.05). Conclusions: Risk factors for CRPA infection or colonization were prior exposure to carbapenems, the days of carbapenems treatment, and co-carriage with Escherichia coli. The prevalence of CRPA could be influenced by Gram-negative pathogens, especially in Escherichia coli, and it need more researches. Moreover, restrictions in the clinical use of carbapenems should be taken into account.