Duration of Colonization with Multiresistant Bacteria after Intensive Care Unit Hospitalization

Abstract

Antimicrobial resistance is an increasing problem in the intensive care unit (ICU), and the persistence of colonization with multidrug-resistant bacteria (MRB) may play an important role in the spreading of these bacteria. The duration of colonization with MRB is not well defined, especially after ICU discharge. The knowledge of MRB persistence in hospitalized and readmitted patients may influence prevention measures. The duration of colonization, and its characterization, may depend on several factors: type of MRB, antibiotic treatment, repeated hospitalizations, sensitivity of the microbiological tests used (cultures, polymerase chain reaction [PCR]). Most of the studies were performed in hospitalized patients colonized with MBR and readmitted to the ICU. These studies show the complexity of factors influencing the duration of colonization and show that median time until MRB clearance may increase to several months. Long-term carriages are reported in several studies for different MRB: MRSA (1–4 years), ESBL-producing enterobacteria (3 years), vancomycin-resistant enterococcal (50 weeks), carbapenem-resistant enterobacteria (1 year), multidrug-resistant Acinetobacter baumannii (42 months). Antibiotics play a major role in the emergence of MRB, and are a risk factor for persistent carriage.