Methicillin-resistant Staphyloccocus aureus in the community

Methicillin-resistant Staphylococcus aureus (MRSA) has become a major nosocomial pathogen worldwide since the 1960's. For decades the bacteria was almost exclusively associated with healthcare settings. However, community outbreaks have emerged in the 1990's and since then the prevalence of MRSA infections is rapidly increasing in the community. Community-acquired MRSA (CA-MRSA) differs from healthcare-associated MRSA (HA-MRSA) in terms of its epidemiological, clinical, and bacteriological characteristics. Reports of outbreaks caused by CA-MRSA are usually related to "closed populations". Most outbreaks have been linked with a single-clone strain and affected individuals are otherwise healthy with no known risk factors for acquisition of the bacteria. The spectrum of disease caused by CA-MRSA has changed in recent years and new syndromes vary from minor skin and soft tissue infections to rapidly overwhelming and often fatal infections. Also, CA-MRSA differs from the nosocomial strain regarding the bacteriologic characteristics which include different antimicrobial susceptibility profiles and the presence of certain virulence factors and exotoxins. Because CA-MRSA is generally not multidrug resistant, good therapeutic options are still available. To provide an effective therapy is necessary to first have the clinical suspicion. Therefore, physicians should be aware of the clinical and epidemiological characteristics of this emergin infection in the community.