Colonization With Methicillin-Resistant Staphylococcus aureus Upon Intensive Care Unit Admission: Incidence and Risk Factors

Background: Since earlier identification of methicillin-resistant Staphylococcus aureus (MRSA)-colonized patients could be helpful for reducing the overall frequency of S. aureus infections, the investigation of persons colonized with MRSA is considered to be a key component of MRSA infection prevention programs, particularly among ICU patients. Objectives: The aim of the present study was to evaluate the prevalence of nasal and extra-nasal carriers of MRSA and risk factors associated with MRSA colonization among adult patients admitted to the ICU. Methods: In a cross-sectional study, ۱۶۴ adult patients who were admitted to the ICU of a teaching hospital were screened for nasal and extra-nasal carriage of MRSA. In addition, the ICU-hospitalized patients were evaluated for MRSA acquisition during their ICU stay. Results: Out of the ۱۶۴ patients admitted to the ICU, ۱۲ (۷.۳%) patients were methicillin-susceptible Staphylococcus aureus (MSSA) carriers, and ۱۲ (۷.۳%) patients carried MRSA. Four (۱۶.۶%) patients were colonized at single or multiple extra-nasal sites based on negative nares screening. Of the ۱۵ remaining patients hospitalized at the ICU, one (۶.۷%) patient acquired MRSA. The patients colonized with MRSA had more advanced ages (P = ۰.۰۰۸), longer hospital stays before being transferred to the ICU (P > ۰.۰۰۱), more underlying diseases with chronic obstructive pulmonary disease (COPD) (P = ۰.۰۲۸), and had undergone surgery (P = ۰.۰۰۳). Patients transferred from the surgical wards to the ICU were found to have significantly higher carriage rates of MRSA (P = ۰.۰۴۱). Conclusions: The prevalence of MRSA colonization upon ICU admission at our hospital was relatively high, and routine MRSA screening is suggested, especially for patients who have certain risk factors. In addition, extra-nasal MRSA screenings upon ICU admission will help in the early detection of MRSA.