Clinical and microbiological characteristics of severe group A streptococcus infections and streptococcal toxic shock syndrome.

We have monitored all cases of invasive group A streptococcus (GAS) infection that have occurred at the New York Hospital (New York) since 1989. Five cases of GAS infection and shock were identified between 1990 and 1991, and an additional case was recently identified at an affiliated hospital. Five of the six patients met the case definition for streptococcal toxic shock syndrome (strep TSS). Three were bacteremic, and four had aggressive soft-tissue infections. Patients with shock, for whom the mortality was higher, had fewer underlying illnesses than did patients who had GAS bacteremia without shock. Although the M1 serotype and production of streptococcal pyrogenic exotoxin A were more common in patients with GAS infection and shock, several patients with strep TSS were infected with a nontypable strain of GAS that produced only streptococcal pyrogenic exotoxin B. In addition, we observed a distinctive early hemodynamic profile for patients with strep TSS that was unlike that for patients who had typical gram-negative septic shock; this profile was consistent with toxic cardiomyopathy (i.e., relatively low cardiac output, low-to-normal systemic vascular resistance, and striking reduction in ventricular performance.