MRSA screening in emergency department detects a minority of MRSA carriers.

INTRODUCTION: Methicillin-resistant Staphylococcus areus (MRSA) is an emerging problem. The Danish Health and Medicines Authority (HMA) has developed a question-based screening tool to identify patients with MRSA. The tool has three parts: questions on general risk situations, special risk situations and individual risk factors. The emergency departments (ED) play a key role in the prevention of in-hospital spreading of MRSA. The aim of the present study was to estimate the prevalence of MRSA among all admitted ED patients to assess how many patients should be swab-tested for MRSA and isolated and to evaluate the ability of the HMA screening tool to detect MRSA.
METHODS: Patients who were more than ten years old answered all the HMA questions on general and specific risk situations and individual risk factors for MRSA, and a swab was obtained for MRSA culture.
RESULTS: A total of 1,945 patients were admitted and 73% participated. Indications for swab testing for MRSA were present in 8%. The general risk situation questions identified 3% for isolation due to suspicion of MRSA. A total of 11 patients had a positive MRSA swab culture (0.9%). Among the isolated patients, 3% had MRSA, 97% would have been isolated unnecessarily, while 91% of the MRSA patients would not have been isolated. The general risk situation questions had a sensitivity of 18-27% and the whole questionnaire had a sensitivity of 55% for the detection of MRSA patients.
CONCLUSIONS: The majority of MRSA carriers who are acutely admitted to the ED will remain undetected. FUNDING: Hospital of Southern Jutland. TRIAL REGISTRATION: not relevant.