Infections due to community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) are increasing worldwide(1). Persons at particular risk of CA-MRSA include children, First Nations populations, athletes, military trainees, men who have sex with men, intravenous drug users, prison populations and the homeless(1-3).While CA-MRSA is less common in Canada than in the United States, several studies have documented its emergence in Canada(4-6). ..
While most CA-MRSA infections are of skin or soft tissue, necrotizing pneumonia due to CA-MRSA is well described and often fatal, even when it occurs in young, immunocompetent people(8). In one comparison of community and hospital-associated MRSA pneumonia, patients with CA-MRSA pneumonia were younger (14.8 years versus 70.1 years), more commonly had influenza-like illness before admission for pneumonia, high temperatures (> 39o C), heart rate > 140 beats per minute and lower survival rates at 48 hours after admission (63% versus 94%)(8). Other recent studies highlight the association between severe community-acquired pneumonia due to S. aureus and preceding viral infection. It has been proposed that a viral infection preceding S. aureus pneumonia may lead to severe necrotizing pneumonia, resulting in admission to the intensive care unit (ICU), intubation and often death(9,10).
