Community-associated Staphylococcus aureus infections: pneumonia

Abstract

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is an emerging health problem with distinct epidemiology. CA-MRSA colonization and infection is associated with risk factors different from healthcare-associated methicillin-resistant S. aureus infection. CA-MRSA strains pre­sent different characteristics to healthcare associated strains in terms of microbiology as well. Moreover, infection as a result of CA-MRSA may be associated with severe infections, in particular necrotizing pneumonia. CA-MRSA strains may produce Panton-Valentine leukocidin, a protein that available data suggest to be associated with the severity of the infection. Although the incidence of CA-MRSA pneumonia is relatively low, it affects mostly young, immunocompetent individuals, and in this respect constitutes a serious and potentially lethal form of community-acquired pneumonia. Current treatment suggested by international consensus guidelines includes linezolid or vancomycin often combined with clindamycin and/or rifampicin. However, clinical studies are required to clarify further therapeutic issues on timing, dosing, and choice of optimum treatment, and whether new therapeutic strategies such as vaccination and immunoglobulins could be useful. In the present review we discuss the microbiology, epidemiology, pathogenesis, and clinical aspects of community-acquired pneumonia as a result of CA-MRSA in respect of management and prevention.