Meticillin-resistant Staphylococcus aureus blood-stream infection among patients attending the emergency department of an urban tertiary-referral hospital.

Meticillin-resistant Staphylococcus aureus (MRSA) is an important nosocomial pathogen but reports of community-acquired (CA) MRSA are increasing. This study determined the incidence of MRSA-blood-stream infection (BSI) among patients attending the Emergency Department (ED) of an urban tertiary-referral hospital between January 2004 and September 2005, the proportion of cases that were CA or health-care associated (HCA), the epidemiological types of isolates and the presence of pvl genes in CA-MRSA. Eighteen patients presented with MRSA-BSI; 16 cases were categorised as HCA and two as CA. Most patients were male, elderly and lived locally. Two patients (aged <30 years) had no recent previous HC exposure. Only one patient received appropriate empiric antimicrobial therapy. Isolates from patients with HCA-MRSA were similar to the predominant MRSA strain in Irish hospitals. The two CA-MRSA isolates exhibited different epidemiological types; one was pvl-positive. A significant cohort of patients present to the ED with MRSA-BSI. Careful consideration of appropriate empiric antimicrobial therapy for suspected staphylococcal infection is required.