Streptococcal Toxic Shock Syndrome (STSS) (Streptococcus pyogenes)
1995 Case Definition

Clinical Description

The streptococcal toxic shock syndrome is a severe illness associated with invasive or noninvasive group A streptococcal (Streptococcus pyogenes) infection. STSS may occur with infection at any site, but most often occurs in association with infection of a cutaneous lesion. Signs of toxicity and a rapidly progressive clinical course are characteristic, and the case fatality rate may exceed 50%.

Clinical Criteria

An illness with the following clinical manifestations occurring within the first 48 hours of hospitalization or, for a nosocomial case, within the first 48 hours of illness:

• Hypotension defined by a systolic blood pressure less than or equal to 90 mm Hg for adults or less than the fifth percentile by age for children less than 16 years of age.
• Multi-organ involvement characterized by two or more of the following:
  • Renal impairment: Creatinine greater than or equal to 2mg/dl (greater than or equal to 177 µmol/L) for adults or greater than or equal to twice the upper limit of normal for age. In patients with pre-existing renal disease, a greater than or equal to 2-fold elevation over the baseline level.
  • Coagulopathy: Platelets less than or equal to 100,000/mm³ (less than or equal to 100 x 10⁶/L) or disseminated intravascular coagulation defined by prolonged clotting times, low fibrinogen level, and the presence of fibrin degradation products.
  • Liver involvement: Alanine aminotransferase, aspartate aminotransferase, or total bilirubin levels greater than or equal to twice the upper limit of normal for the patient's age. In patients with pre-existing liver disease, a greater than or equal to 2-fold increase over the baseline level.
  • Adult respiratory distress syndrome: defined by acute onset of diffuse pulmonary infiltrates and hypoxemia in the absence of cardiac failure; or evidence of diffuse capillary leak manifested by acute onset of generalized edema, or pleural or peritoneal effusions with hypoalbuminemia.
  • A generalized erythematous macular rash that may desquamate.
  • Soft-tissue necrosis, including necrotizing fascitis or myositis, or gangrene.

Laboratory Criteria For Diagnosis

Diagnosis is based on laboratory isolation of group A Streptococcus.

Probable

Isolation of group A Streptococcus from a nonsterile site in a patient with illness that meets the clinical case definition in the absence of another identified etiology for the illness.

Confirmed

Isolation of group A Streptococcus from a normally sterile site in a patient with an illness that meets the clinical case definition.

• Streptococcal Toxic Shock Syndrome (STSS) (Streptococcus pyogenes) | 2010 Case Definition
• Streptococcal Toxic Shock Syndrome (STSS) (Streptococcus pyogenes) | 1996 Case Definition