Staphylococcus aureus bloodstream infection in Australian hospitals: findings from a Victorian surveillance system.

OBJECTIVES

To determine the burden of disease and trend over time for rates of Staphylococcus aureus bloodstream (SAB) infections in Victorian health care services.

DESIGN AND

SETTING

Uniform data on all SAB infection events (methicillin-sensitive and methicillin-resistant isolates) were collected from all public and some private hospitals in Victoria using a standardised electronic data collection tool. Data were analysed for the period 1 January 2010 to 31 December 2012.

MAIN OUTCOME MEASURES: Overall and quarterly aggregate SAB and methicillin-resistant S. aureus (MRSA) bloodstream infection rates per 10,000 occupied bed-days (OBDs); rates of health care-associated (HA) infections compared with a benchmark of no more than 2/10,000 OBDs.

RESULTS

Data from 119 public and four private hospitals were analysed. The cumulative aggregate SAB infection rate was 1.0/10,000 OBDs (95% CI, 0.9-1.0/10,000 OBDs). Overall, 1335/3205 SAB infection events (41.7%) were health care-associated. Of these, 26.2% occurred within 48 hours of hospitalisation and were most frequently associated with an indwelling medical device. Quarterly HA-SAB infection rates diminished from 1.4 to 0.7/10,000 OBDs (P < 0.001). A median of four health care services each quarter exceeded the benchmark of 2.0/10,000 OBDs. HA-MRSA bloodstream infection rates diminished from 0.4 to 0.1/10,000 OBDs (P < 0.001), with a cumulative aggregate rate of 0.2/10,000 OBDs.

CONCLUSIONS

Continuous surveillance for SAB infection showed a significant reduction in rates across Victoria during the first 3 years of a coordinated program. Early onset, device-related SAB infections are an important target for prevention strategies.