The NewClostridium difficile— What Does It Mean?

Recent experience with influenza, the severe acute respiratory syndrome (also known as SARS), avian influenza, and community-acquired methicillin-resistant Staphylococcus aureus has demonstrated how old pathogens can emerge with increased virulence and challenge scientists to explain their rebirth, clinicians to care for patients, and infection-control personnel to prevent their spread. Clostridium difficile appears to illustrate these challenges. It already has some distinctive features: it causes disease almost exclusively in the presence of exposure to antibiotics, it is the only anaerobe that poses a nosocomial risk, and it produces toxin in vivo only in the colon.About 3 percent of healthy adults . . .