Methicillin-resistant Staphylococcus aureus colonization in a pediatric intensive care unit: risk factors

Both methicillin-resistant Staphylococcus aureus (MRSA) and penicillin-resistant Streptococcus pneumoniae have become significant causes of disease, both in health care and community settings.

All patients admitted to our pediatric intensive care unit (PICU) currently had a rapid test for methicillin-resistant Staphylococcus aureus (MRSA) performed as per hospital guidelines. This study looked at risk factors for colonization.

Nasal swabs were tested for MRSA on all admissions to the PICU from May 2008 to September 2009 using polymerase chain reaction as per hospital guidelines. All patients enrolled were placed in either a MRSA-positive or a MRSA-negative group, which were compared with each other. Risk factors were assessed from a questionnaire and the resident history.

The prevalence of MRSA colonization in our study was 4.5%. Six hundred sixty-six patients were negative for MRSA, and 31 were positive. Patients in the MRSA colonization group were younger, more likely had family (household members) employed in medicine, and were more likely hospitalized or had undergone surgery within the previous 12 months. Prolonged neonatal intensive care unit stay (>1 week) was associated with MRSA colonization (P < .001).

The percentage of patients positive for MRSA admitted to a PICU is low. Recent exposure to the health care system, especially a stay in the neonatal intensive care unit, is associated with an increased risk of colonization.