The Evaluation of Risk Factors for Vancomycin-Resistant Enterococcus Colonization and Infection Among Mixed Adult Intensive Care Unit Patients

Background and objective Despite the adherence to strict infection control measures, vancomycin-resistant enterococcus (VRE) colonization and VRE infections are still important problems nowadays. However, there are only a limited number of studies examining the factors causing the transformation of VRE colonization to VRE infection in the intensive care unit (ICU). The aim of this study is to delineate the prevalence of VRE colonization and its transformation into infection and the risk factors leading to infection. Methods Patients admitted to the third-level mixed-type ICU from 2012 to 2015 for at least 24 hours and acquired VRE colonization and VRE infection, both during and after their admission, were included in the study, and their medical records were examined retrospectively. VRE rectal swabs were taken weekly from each patient on admission and discharge from the ICU. If the VRE-positive patient was detected negative for VRE on the rectal swap taken three times in total as a surveillance culture successively, this patient was accepted as VRE negative. Demographic data, Acute Physiology and Chronic Health Evaluation II (APACHE-II) scores, invasive procedures, treatments (corticosteroid, antibiotic, etc.), nutrition types, laboratory results, and ICU results were recorded. Results Among 1730 patients admitted to ICU, 101 (5.8%) were found to carry VRE colonization. Twelve (11.8%) out of 101 patients colonized with VRE developed VRE infection. About 56.4% had urinary tract infections, 68.3% had pneumonia, 15.8% had surgical site infections, and 24.8% had catheter-associated infections among these infected patients. The most prevalent factor was Enterococcus faecium in patients with VRE colonization (64.3%) and infection (91%). VRE turned negative in 67% of patients with VRE colonization during their stay in ICU. Renal replacement therapy was statistically significant (p < 0.05) in the group with VRE infection (66.7%) compared to the VRE-colonized group (26.1%). Infection development risk among carriers of VRE for more than one week was again found statistically significant (p = 0.025). Demographic data, APACHE-II scores, treatments, nutrition type, previous antibiotic usage and types, invasive procedures, laboratory results, and ICU results were similar among the patients with VRE colonization and infection. Conclusion A longer duration of ICU stay in patients with colonization and previous renal replacement therapy increases the transformation of VRE colonization to VRE infection. Strategies toward decreasing VRE-colonized patients' period of stay in ICU is the main objective to control the rate of VRE infection.