Epidemiology and outcomes of community-onset methicillin-susceptible Staphylococcus aureus bacteraemia in a university hospital in Singapore

Background: Methicillin-susceptible Staphylococcus aureus (MSSA) bacteraemia remains a condition associated with considerable morbidity and mortality worldwide. It is a common but little-studied problem outside of Europe and North America. Methods: A single-centre retrospective case series profiling all patients with community onset-MSSA bacteraemia presenting between March 2005 and February 2006 to a tertiary acute-care university hospital in Singapore. In addition to epidemiological and clinical data collection, risk factors for complicated bacteremia and attributable mortality were analysed. Results: A total of 100 patients met the case definition. Patients were more likely to be male (65%) and below 65 years of age (69%). Seventeen patients were intravenous drug abusers, while 38 had diabetes mellitus. There were 18 cases of endocarditis, with 11 occurring in intravenous buprenorphine abusers. Attributable mortality was 11%, and 46% of patients developed complicated bacteremia. On multivariate analysis, age > 65 years and presence of chronic pulmonary disease were the only significant risk factors for the former, while valvular heart disease was a significant risk factor for the latter. Conclusion: MSSA bacteraemia is associated with a significant risk of serious complications in Singapore. Other Asian cities should be alert to the risk factors for adverse outcomes for this important cause of morbidity and mortality.