Surveillance for severe community-associated methicillin-resistant Staphylococcus aureus infection

Abstract

SUMMARYCommunity-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has rapidly emerged in the USA as a cause of severe infections in previously healthy persons without traditional risk factors. We describe the epidemiology of severe CA-MRSA disease in the state of Georgia, USA and analyse the risk of death associated with three different clinical syndromes of CA-MRSA disease – pneumonia, invasive disease, and skin and soft-tissue infections (SSTIs). A total of 1670 cases of severe CA-MRSA disease were reported during 2005–2007. The case-fatality rate was 3·4%; sex and race of fatal and non-fatal cases did not differ significantly. While CA-MRSA pneumonia and invasive disease were less common than SSTIs, they were about 15 times more likely to result in death [risk ratio 16·69, 95% confidence interval (CI) 10·28–27·07 and 13·98, 95% CI 7·74–25·27, respectively]. When controlling for age and the presence of other clinical syndromes the odds of death in patients manifesting specific severe CA-MRSA syndromes was highest in those with pneumonia (odds ratio 11·34). Possible risk factors for severe CA-MRSA SSTI and pneumonia included the draining of lesions without medical assistance and an antecedent influenza-like illness.