Definitions

A new MRSA episode was defined as at least one positive respiratory sample culture (sputum or oropharyngeal swab) from a person whose previous respiratory cultures (during the previous 12 months) were negative for MRSA. MRSA was considered successfully eradicated if all respiratory samples, during the 6-month period following eradication treatment, were MRSA culture negative. A minimum of two cultures, collected after the end of systemic antibiotic treatment, were required to fulfil the eradication criteria. Patients who had at least two MRSA-positive sputum cultures over a 6-month period prior to the first eradication attempt were defined as chronically infected with MRSA.