The role of the intensive care unit environment and health-care workers in the transmission of bacteria associated with hospital acquired infections

Abstract

The goal of this study was to attempt to determine the rate of contamination of health-care workers' (HCWs) hands and environmental surfaces in intensive care units (ICU) by the main bacteria associated with hospital acquired infections (HAIs) in Tehran, Iran. A total of 605 and 762 swab samples were obtained from six ICU environments and HCWs' hands. Identification of the bacterial isolates was performed according to standard biochemical methods, and their antimicrobial susceptibility was determined based on the guidelines recommended by clinical and laboratory standards institute (CLSI). The homology of the resistance patterns was assessed by the NTSYSsp software. The most frequent bacteria on the HCWs' hands and in the environmental samples were Acinetobacter baumannii (1.4% and 16.5%, respectively), Staphylococcus aureus (5.9% and 8.1%, respectively), S. epidermidis (20.9% and 18.7%, respectively), and Enterococcus spp. (1% and 1.3%, respectively). Patients' oxygen masks, ventilators, and bed linens were the most contaminated sites. Nurses' aides and housekeepers were the most contaminated staff. Imipenem resistant A. baumannii (94% and 54.5%), methicillin-resistant S. aureus (MRSAs, 59.6% and 67.3%), and vancomycin resistant Enterococci (VREs, 0% and 25%) were detected on the hands of ICU staff and the environmental samples, respectively. Different isolates of S. aureus and Enterococcus spp. showed significant homology in these samples. These results showed contamination of the ICU environments and HCWs with important bacterial pathogens that are the main risk factors for HAIs in the studied hospitals.

Keywords: Bacterial contamination; Drug resistance; Health care workers; Hospital acquired infections; Hospital environment; Intensive care units.