Prior Carriage Predicts Intensive Care Unit Infections Caused by Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae

Intensive care unit-acquired infection (ICU-AI) and extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) carriage are a major concern worldwide. Our objective was to investigate the impact of ESBL-PE carriage on ICU-AI. Our study was prospective, observational, and noninterventional. It was conducted over a 5-year period (Jan 2013-Dec 2017) in the medical-surgical intensive care unit of the Cayenne General Hospital (French Amazonia). During the study period, 1,340 patients were included, 271 (20.2%) developed ICU-AI, and 16.2% of these were caused by ESBL-PE. The main sites of ICU-AI were ventilator-associated pneumonia (35.8%) and primary bloodstream infection (29.8%). The main responsible microorganisms were Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae (ESBL-P in 35.8% of isolates), and Enterobacter cloacae (ESBL-P in 29.8% of isolates). Prior ESBL-PE carriage was diagnosed in 27.6% of patients with ICU-AI. In multivariable analysis, the sole factor associated with ESBL-PE as the responsible organism of ICU-AI was ESBL-PE carriage before ICU-AI (P < 0.001; odds ratio: 7.9 95% CI: 3.4-18.9). ESBL-PE carriers (74 patients) developed ICU-AI which was caused by ESBL-PE in 32 cases (43.2%). This proportion of patients carrying ESBL-PE who developed ICU-AI to the same microorganism was 51.2% in ESBL-P K. pneumoniae, 5.6% in ESBL-P Escherichia coli, and 40% in ESBL-P Enterobacter spp. NPV of ESBL-PE carriage to predict ICU-AI caused by ESBL-PE was above 94% and PPV was above 43%. Carriage of ESBL-P K pneumoniae and Enterobacter spp. is a strong predictor of ICU-AI caused by these two microorganisms.