Epidemiology and outcomes for Staphylococcus aureus bacteraemia in Australian hospitals, 2005-06: report from the Australian Group on Antimicrobial Resistance.

The Australian Group on Antimicrobial Resistance studied the epidemiology and outcomes of Staphylococcus aureus bacteraemia in selected Australian hospitals in 2005-06. Seventeen hospital-based laboratories collected basic demographic, susceptibility and patient outcome data on all cases of S. aureus bacteraemia for 5 to 24 months during the study period. There were 1,511 cases of bacteraemia documented, of which 66% occurred in males and 32% originated from vascular access devices. Bacteraemia had a community onset in 60% of cases, although 31% of these were health-care associated. Overall, 57% of episodes were health-care related. Methicillin-resistant Staphylococcus aureus (MRSA) was the responsible pathogen in 24% of instances; of these 53% were of the typical multi-resistant hospital type, and 29% were of the community-associated type. Seven per cent of all staphylococcal bacteraemias were caused by community-associated MRSA strain types, attesting to the growing size of this problem in Australia. Outcomes were available for 51% of cases and in those the all-cause mortality at 7 days or discharge (whichever came earlier) was 11.2%. Age was strongly associated with mortality; the rate for patients aged more than 60 years was 18%. Sepsis originating from intravascular access devices had a lower mortality rate of 5%. S. aureus bacteraemia is a common community and hospital infection with a significant mortality. A nationally co-ordinated program documenting the incidence and outcomes of this disease would likely lead to measures designed to reduce the incidence and improve outcomes of this disease.