Toxic shock syndrome
Acute Life-Threatening Group A Streptococcal Infections
Dennis L. Stevens, Ph.D., M.D
Recently, severe invasive GAS infections associated with shock and organ failure have been reported with increasing frequency, predominantly from North America and Europe (8-18). These infections have been termed streptococcal toxic-shock syndrome (TSS; Table 1) (19). Persons of all ages are affected; most do not have predisposing underlying diseases (11,20-25). This is in sharp contrast to previous reports of GAS bacteremia, in which patients were either under 10 or over 60 years of age, and most had underlying conditions such as cancer, renal failure, leukemia, or severe burns or were receiving corticosteroids or other immunosuppressing drugs (20-22). The complications of current GAS infections are severe; bacteremia associated with aggressive soft tissue infection, shock, adult respiratory distress syndrome and renal failure are common; 30% to 70% of patients die in spite of aggressive modern treatments (Table 2) (1,8,24-26).
Table 1. Case definition of streptococcal toxic-shock syndrome
(streptococcal TSS) and necrotizing fasciitis*
I. Streptococcal TSS
A. Isolation of group A Streptococcus
1. From a sterile site
2. From a nonsterile body site
B. Clinical signs of severity
2. Clinical and laboratory abnormalities (requires two or
more of the following):
d)Acute respiratory distress syndrome
e)Extensive tissue necrosis, i.e., necrotizing fasciitis
Definite Case = A1 + B(1+2)
Probable Case = A2 + B(1+2)
II. Necrotizing fasciitis
A. Definite case
1. Necrosis of soft tissues with involvement of the fascia
2.Serious systemic disease, including one or more of the
b)Shock (systolic blood pressure <90 mm of Hg).
c)Disseminated intravascular coagulopathy
d)Failure of organ systems a.respiratory failure b.liver failure c.renal failure
3.Isolation of group A Streptococcus from a normally sterile
1.1+2 and serologic confirmation of group A streptococcal
infection by a 4-fold rise against:
2.1+2 and histologic confirmation:
Gram-positive cocci in a necrotic soft tissue infection
*Streptococcal toxic-shock syndrome (streptococcal TSS) is
defined as any group A streptococcal infection associated with
the early onset of shock and organ failure. Definitions
describing criteria for shock, organ failure, definite cases,
and probable cases are included below.
Source: reference 61.
Table 2. Complications of group A streptococcal soft-tissue
Complication of Patients
Acute respiratory distress syndrome 55
Renal impairment 80
Source: reference 1.
Acquisition of Group A Streptococcus
The portal of entry of streptococci cannot be proven in at least half the cases (8) and can only be presumed in many others.
Patients with symptomatic pharyngitis rarely develop streptococcal TSS, though such cases have been reported,especially in the last year.
Procedures such as suctionlipectomy, hysterectomy, vaginal delivery, bunionectomy and bone pinning have provided a portal of entry in many cases (author's unpublished observations).
Most commonly, infection begins at a site of minor local trauma, which frequently does not result in a break in the skin (8).
Numerous cases have developed within 24 to 72 hours of minor nonpenetrating trauma, resulting in hematoma, deep bruise to the calf, or even muscle strain.
Virus infections, such as varicella and influenza, have provided a portal in other cases. In some cases the use of nonsteroidal antiinflammatory agents may have either masked
the early symptoms or predisposed the patient to more severe streptococcal infection and shock (1).
For the most part, these infections have occurred sporadically and have not been associated with clusters of cases or minor epidemics,
though outbreaks of severe GASinfections have occurred in closed environments such as nursing homes (27,28).