Group A streptococcal (GAS) bacteremia
GAS bacteremia の復習から
Group A streptococcal (GAS) bacteremia occurs following development of infection at a primary site of infection; GAS bacteremia occurs most commonly in the setting of skin and soft tissue infection. Other forms of infection include pharyngitis, pneumonia, and postpartum endometritis, and toxic shock syndrome.
Streptococcal bacteremia is most common in the very young and in older adults, although infection may occur in patients of any age, and most patients are not immunosuppressed.
Risk factors in adults under 40 include postpartum infection, intravenous drug use, and HIV infection.
The most common source of GAS bacteremia in adults is skin and soft tissue infection, including cellulitis, erysipelas, pyoderma, injection drug use, burns, varicella virus infection, necrotizing fasciitis, and spontaneous gangrenous myositis. Deep soft tissue infections may also be associated with shock and organ failure.
Treatment of GAS bacteremia requires a multidisciplinary approach including antibiotic management, surgical debridement (if warranted), and management of septic physiology (if present).
We recommend penicillin G (4 million units intravenously every four hours in patients with normal renal function) and clindamycin (900 mg intravenously every eight hours) for treatment of GAS bacteremia (Grade 1C).
Clinical failures of penicillin therapy for streptococcal infections do occur; in these settings, clindamycin is especially useful, both because its efficacy is not affected by inoculum size or stage of growth and because it suppresses toxin production.
The duration of antibiotic therapy for GAS bacteremia should be individualized. In general, antibiotics should be administered for at least 14 days
We suggest the use of intravenous immune globulin in patients with invasive GAS infections who develop signs of shock.
GAS bacteremia is a serious infection. The mortality rate of invasive GAS infections ranges from 25 to 48 percent. Shock is the most important predictor of mortality (79 versus 16 percent in those without shock in one series)