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

Area of Science:

• Infectious Diseases
• Epidemiology
• Public Health

Background:

• Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is a growing cause of severe infections in the US.
• CA-MRSA infections occur in individuals without traditional risk factors.

Purpose of the Study:

• To describe the epidemiology of severe CA-MRSA disease in Georgia, USA.
• To analyze the risk of death associated with different CA-MRSA clinical syndromes.

Main Methods:

• Retrospective analysis of 1670 severe CA-MRSA cases reported from 2005-2007.
• Comparison of case-fatality rates across pneumonia, invasive disease, and skin and soft-tissue infections (SSTIs).
• Risk analysis using risk ratios and odds ratios, controlling for age and other clinical syndromes.

Main Results:

• The overall case-fatality rate for severe CA-MRSA was 3.4%.
• CA-MRSA pneumonia and invasive disease were significantly more lethal than SSTIs (RR 16.69 and 13.98, respectively).
• Pneumonia presented the highest odds of death (OR 11.34) when controlling for other factors.

Conclusions:

• Severe CA-MRSA syndromes, particularly pneumonia, carry a substantial risk of mortality.
• Draining lesions without medical care and preceding influenza-like illness may be risk factors for severe CA-MRSA SSTI and pneumonia.