JAMA Editorial: Responding to Decline in MRSA Infection
The emergence of MRSA (methicillin-resistant S aureus) began in the 1990s; since then, community-associated MRSA strains have increasingly caused hospital-onset and healthcare-associated, community-onset infections. However, the initial strains that predominated before 2001 have been replaced by unrelated strains that currently cause the majority of community-associated MRSA infections in the United States. This Editorial reports on the current status of MRSA infection rates – and what it may mean for the future.
Using data from 2005-2008, the CDC’s surveillance system, which encompasses about 15 million Americans in nine metropolitan areas, showed a continuous decline of invasive MRSA disease. This includes an estimated 9.4% annual decrease in hospital onset and an estimated 5.7% annual decrease in healthcare-associated community-onset infections. There are a variety of theories for these decreases, such as general infection control efforts (e.g., wider use of alcohol-based hand rubs). However, it may be presumptuous to assume that hospital-based prevention efforts have a major effect on the natural history of such a wide-spread pathogen. Natural biologic trends, such as the emergence and disappearance of specific clones, are likely to override the best-laid attempts at infection control.
Therefore, although the present decrease in MRSA may be used to argue for or against MRSA-specific vs. general infection prevention interventions, the authors suggest that these arguments would be missing the point. The decreases are occurring for a reason, and only by improving existing surveillance and prevention research programs can clinicians and infection control researchers begin to explain why.
Perencevich E and Diekema D. Decline in invasive MRSA infection: Where to go from here? JAMA Editorial August 11, 2010(304(6):687-689.
Dr. Perencevich is part of HSR&D’s Center for Research in Implementation of Innovative Strategies in Practice, Iowa City, IA.