Secular Trends in Staphylococcus aureus Bloodstream Infections over Four Decades
The epidemiology of bloodstream infections due to Staphylococcus aureus (SA-BSI) has changed dramatically over the last several decades with the widespread use of intravascular catheters, the emergence and spread of methicillin resistant S. aureus (MRSA) and the rise of community-onset infections. We examined secular trends in SA-BSI occurring from 1980 to 2013 with particular focus on MRSA, source of BSI and location of onset.
Records were reviewed for all patients with SA-BSI who were hospitalized at one academic medical center. Rates of SA-BSI per 1,000 discharged patients were calculated for the first four years of four decades (1980-1983, 1990-1993, 2000-2003 and 2010-2013). Temporal trends were assessed for proportion of SA-BSI due to MRSA and attributed source.
Rates of SA-BSI increased from the 1980-3 study period through the 2000-3 study period however both hospital-onset and community-onset BSIs decreased in the last study period (Figure). In the 1980-3 study period there was only one central line-associated BSI (CLABSI) and two MRSA BSIs. The increase in SA-BSI through 2000-3 was driven by an increase in CLABSI for both hospital-onset and community-onset BSIs; in the 2000-3 period, 75/235 hospital-onset and 166/400 community-onset SA-BSIs (127 of which were dialysis catheter related) were CLABSIs. Hospital-onset SA-BSI decreased by 48% in the 2010-13 period with 51/123 SA-BSI being CLABSIs. Since 2000-3, MRSA has accounted for about half of all SA-BSI although there was a decrease in the proportion of hospital-onset SA-BSI caused by MRSA over the last two study periods, from 57.0% in 2000-3 to 41.5% in 2010-13.
There was an increase in SA-BSI in the first three decades of the study period, in large part due to CLABSIs in and outside the hospital. In the last decade there has been a decrease in SA-BSI, with a marked decrease in hospital-onset infections, including a decrease in CLABSI. While MRSA still causes almost half of all SA-BSI, there was a notable decrease in hospital-onset MRSA in recent years.
S. Cali, None
J. Jacob, None
J. Steinberg, None