Determination of risk factors for vancomycin resistant enterococcus colonization and infection in newborns

Introduction and Aim: Enterococci occupy an important place among the infectious agents. Structurally existing and acquired resistance properties against commonly used antibiotics have made enterococci even more problematic microorganisms. The most important developing resistance is vancomycin resistance. Infections caused by vancomycin-resistant enterococci (VRE) are difficult to treat and the number of antibiotics that can be used in the treatment is limited. In the literature, it is seen that there are many studies of VRE colonization and infections in adult intensive care and hemodialysis units. However, the number of studies conducted in neonatal intensive care units (NICUs) is very low. In this group, which is very sensitive and vulnerable to infections, preventing infections before they occur will reduce long-term intensive care hospitalizations and antibiotic use. The aim of this study was to determine the risk factors for VRE colonization and infection in infants followed in the neonatal intensive care unit. Material Method: The study was conducted as a retrospective case-control study. In the study, the sample size was not calculated because the archive was scanned. Between 01.01.2015 and 31.12.2020, preterm and term 0-30 days old infants hospitalized in the NICU of our hospital for any reason were included in the study. Among the patients whose perirectal swab culture was taken, those who were found to be positive for VRE were included in the patient group, and those who were found negative and matched with the patient group were included in the control group. Those who did not have a perirectal swab culture, patients who were not hospitalized in Adnan Menderes University Neonatal ICU between 01.01.2015-31.12.2020, patients who were older than 30 days were not included in the study. Results: A total of 54 infants, 23 (42.6%) female and 31 (57.4%) male, were included in the study. The median age of the infants was 35.0 (24.0-41.0) days, the median birth weight was found to be 2445.0 (570.0-3555) grams. The median hospitalization duration of the infants was 13.5 (0.0-566.0) days, the median total parenteral nutrition duration was 1.0 (0.0-135.0) days, and the median follow-up duration on ventilator was 0.5 (0.0-147) days were determined. In addition, it was observed that the infants were VRE positive on the median 6.0 (1.0-91.0) day of hospitalization. VRE growth was detected in 6 (11.1%) blood cultures, 2 (3.7%) urine cultures, and 3 (5.6%) tracheal aspirate cultures from infants. In addition, it was determined that VRE was grown in only 1 (1.9%) culture. It was observed that 18 (33.4%) of the infants were hospitalized with prematurity, 9 (17.1%) were hospitalized with respiratory distress, and 8 (14.9%) were hospitalized with hyperbilirubinemia. The most commonly administered antibiotics to infants were amikacin (50.0%), ampicillin (50.0%), and vancomycin (27.8%), respectively. Discussion and Conclusion: Detection of risk factors for VRE colonization and infection is important in terms of determining the measures to be taken. In the literature, length of hospital stay, antibiotic use, and the presence of a catheter were found to be risk factors for VRE. In our study, results were not compatible with the literature and it was determined that the length of hospital stay, antibiotic use, and the presence of a catheter did not pose a risk for VRE colonization. In the Aydın study, it was thought that the lack of a significant relationship between these risk factors and VRE colonization, in line with the literature, may be due to the low length of hospital stay in our study. The result found in the Aydın study suggests that the low length of hospital stay reduces the effects of VRE colonization risk factors.