Author — Alex Kallen, MD, MPH
CDC Division of Healthcare Quality Promotion
Few people would disagree with me that reducing the number of devastating healthcare-associated methicillin-resistant Staphylococcus aureus (MRSA) infections continues to be important. We now have some encouraging results from CDC’s Emerging Infections Program/Active Bacterial Core Surveillance system (ABCs) that MRSA infections acquired in the healthcare setting are on the decline. This important laboratory-based surveillance system has tracked rates of serious invasive MRSA infections since mid-2004 in nine diverse metropolitan areas in the U.S.
A recent analysis of data has shown about a 28% decrease in invasive MRSA infections that had onset in the hospital from 2005 through 2008. Decreases in infection rates were even larger for the subset of patients with bloodstream infections. Even more interesting to me, was a 17% drop over the same time period in invasive MRSA infections that had onset in the community but occurred in people with recent exposures to healthcare settings.
Although the reduction of these invasive infections was substantial, the reasons behind the decreased rates are not completely clear. The fact that rates fell more in hospitals than outside of hospitals might argue that at least some of the drop was due to MRSA prevention activities that are going on in those facilities. As most of the infections captured by this surveillance system were bloodstream infections, device-specific prevention activities like the implementation of CDC Healthcare Infection Control Practice Advisory Committee (HICPAC) evidence-based central line insertion practices could explain some or all of this decrease.
Another important point raised in this study is the increasing role of state health departments in these issues. This surveillance system is based at state health departments and demonstrates the important contribution of state and local health departments in the prevention of healthcare-associated infections.
This research complements data from the National Healthcare Safety Network (NHSN) that found rates of MRSA bloodstream infections fell nearly 50% from 1997 to 2007. Taken together, these studies provide even stronger evidence that rates of these infection are truly falling in the United States. While MRSA remains an important public health problem and more remains to be done to decrease rates of these infections further, this decrease in serious MRSA infections is welcome and encouraging news.