Nosocomial outbreak of community strain of methicillin-resistant Staphylococcus aureus in an acute inpatient traumatic brain injury rehabilitation unit

Abstract

BACKGROUND: A cluster of methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) soft tissue infections (STIs) was identified in three patients on a 27-bed acute inpatient traumatic brain injury (TBI) unit in an acute rehabilitation hospital during spring 2004. The initial outbreak was limited to one area on the unit. Sensitivity patterns were the same and suggested a community strain of MRSA. One week later another patient developed a STI. METHODS: Outbreak investigation included review of staff assignments, environmental cleaning, handwashing practices, and patient infections status at admission. Unit was cleaned. We installed several freestanding alcohol gel dispensers to increase hand hygiene options. Admission and weekly MRSA screen from the patients' nares were collected until no new cases were seen. Environmental cultures of patient shared equipment were collected. Twelve MRSA isolates were sent for pulsed-field gel electrophoresis (PFGE) testing. RESULTS: PFGE testing demonstrated the same clonal strain in 8 of the 12 samples. These matched the patterns from the LA community-acquired strain. Seven patients were colonized/infected with the same community strain of MRSA. The environmental samples did not yield any significant organisms. Personal items of patients with MRSA such as wheelchairs, siderails, and helmet grew significant growths of MRSA. No MRSA infections were identified in staff during this period. Patients with MRSA STIs received chlorohexidine showers and intranasal bactroban for 5 days. MRSA colonization persisted in three patients. Education about MRSA transmission and prevention was provided to patients, family, and staff with the primary focus on hand hygiene. Although environmental sampling demonstrated no evidence of transfer of the organism via shared equipment, the process for cleaning common shared items such as therapy mats, shower chairs, and dining room tables was reinforced with staff. CONCLUSION: This outbreak was unusual – nosocomial transmission of community strain of MRSA in a TBI unit in an acute physical rehabilitation facility where patients are encouraged to ambulate freely and use shared treatment spaces. Transmission most likely occurred via the hands of the patients or healthcare workers. There has been no reoccurrence since interventions were instituted.