Risk factors for intensive care unit acquired nasal colonization of MRSA and its impact on MRSA infection

Objective: We aimed to determine the risk factors of methicillin-resistant Staphylococcus aureus (MRSA) colonization, and the impact of colonization on MRSA infection to evaluate the necessity of MRSA survey program in intensive care units (ICUs) in Turkey. Methods: The patients hospitalized in medical and neurosurgical ICUs longer than 24 hr were included into the study. To determine anterior nares MRSA colonization, swabs were taken from each patient in the first 48 hr, and followed by once a week till discharge from ICUs. Results: During the one-year follow-up period, the number of the hospitalized patients who spent more than 24 hr in ICUs was 195 of 372 and 85 of 619 in medical and neurosurgical ICUs, respectively. Totally, 23 out of 280 patients (14 from medical ICU, 9 from neurosurgical ICU) were colonized with MRSA, and 11 out of 23 colonized patients were accepted as ICU-acquired infection. The duration of ICU hospitalization in patients with ICU-acquired MRSA colonization was found to be longer than the noncolonized patients (18 days vs. 8 days, P value < 0.001). The presence of gastrostomy and femoral catheter were determined as risk factors for ICU-acquired MRSA colonization. The percentages of MRSA infection in patients with and without MRSA colonized were 8.6% and 1.1%, respectively (P value: 0.009). Conclusion: The presence of gastrostomy and femoral catheter, and the duration of ICU hospitalization were found to be related with ICU-acquired MRSA colonization. Also, MRSA nares colonization increased the rates of both MRSA infection and ICU hospitalization.