Streptococcal Disease



  • Increase in frequency of aggressive streptococcal necrotizing skin infection noted in 1980s and dubbed “flesh-eating bacteria”
  • Affects otherwise healthy patients aged 20–50 yr who did not have underlying predisposing diseases
  • Rapid progression of shock and multiorgan dysfunction, with death occurring within 1–2 d
  • Incidence is 3–4 per 100,000 in industrialized countries
  • Invasive infections caused by group A Streptococcus (GAS) include:
    • Necrotizing fasciitis (NF):
      • Progressive, rapidly spreading soft tissue infection located within the deep fascia and subcutaneous fat
    • Streptococcal toxic shock syndrome (STSS):
      • May occur in patients with GAS-associated NF
      • Portals of entry for streptococci include vagina, pharynx, mucosa, and skin
      • Unknown cause in 50% of cases
    • “Other” invasive disease defined as isolation of GAS from a normally sterile body site (i.e., sepsis, bacteremic pneumonia, septic arthritis, etc.)
  • Occurs sporadically, with occasional outbreaks in long-term care facilities and hospitals
  • Rate of invasive GAS disease 6 times the annual incidence of meningococcal disease

STSS Case Definition
  • Isolation of GAS from sterile or nonsterile body site
  • Hypotension
  • 2 or more of the following:
    • Renal impairment
    • Coagulopathy
    • Liver abnormalities
    • Acute respiratory distress
    • Extensive tissue necrosis (NF)
    • Erythematous rash


  • NF:
    • GAS is causative in 10% of cases. Blunt trauma is risk factor
    • Mixed anaerobic and aerobic organisms are found in 70% of cases
    • Staphylococcus aureus, Clostridium species, and other enteric organisms
  • STSS:
    • Occurs when susceptible host is infected with virulent strain
    • M protein types 1, 3, and 28 are most common
    • Pyrogenic exotoxins (e.g., A, B, and C) produce fever and shock via activation of tumor necrosis factor and interleukins
    • Nonsteroidal anti-inflammatory drugs appear to mask or predispose patients
    • Risk factors:
      • Age <10 or >60 yr
      • Cancer
      • Renal failure
      • Leukemia
      • Severe burns
      • Corticosteroids

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