Methicillin-Resistant Staphylococcus aureus (MRSA): Prevalence and Epidemiology Issues

Extract

Awareness of the threat of MRSA is growing. Scientists have put a lot of effort into trying to divide and classify MRSA strains into groups to better understand it. This led to the discovery that the resistance gene, mecA, and surrounding DNA could be grouped into several types. It was also discovered that the MRSA strains that caused hospital-acquired (nosocomial) infections were different strains than those seen in the communities. Several studies led to the realization that the number of MRSA infections is increasing, that more Staphylococcus aureus infections are caused by MRSA strains, and that the community strains are now showing up in the hospital. There have been government initiatives to try to decrease MRSA infections, with the most perplexing issue being that of whether or not to perform surveillance cultures on as many people as possible to eradicate MRSA from the community, as well as the hospital.

Until a few years ago, the risk associated with MRSA infections was primarily considered a nosocomial issue. But then a growing number of infections were noted as originating in the non-hospital population and studies were initiated to characterize the differences between hospital-acquired (nosocomial) MRSA (HA-MRSA) and community-acquired MRSA (CA-MRSA). Certain criteria were identified to try to distinguish between these. The now accepted designation for CA-MRSA is those strains of MRSA that are isolated from infections in out-patient settings or from hospitalized patients within 48 hours of hospital admission. In addition, these patients must not have had a previous MRSA infection, and…