Streptococcal toxic-shock syndrome (STSS) 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 case definition
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 aged less than 16 years.
Multi-organ involvement characterized by two or more of
the following:
Renal impairment: Creatinine greater than or
equal to 2 mg/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 preexisting renal disease, a greater than twofold 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 preexisting liver disease, a greater than twofold increase over the
baseline level.
Acute respiratory distress syndrome: defined
by acute onset of diffuse pulmonary infiltrates and hypoxemia in the absence
of cardiac failure or by 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 fasciitis
or myositis, or gangrene.
Laboratory criteria for diagnosis
Isolation of group A Streptococcus.
Case classification
Probable: a case that meets the
clinical case definition in the absence of another identified etiology for the
illness and with isolation of group A Streptococcus from a nonsterile
site.
Confirmed: a case that meets the clinical case definition
and with isolation of group A Streptococcus from a normally sterile site
(e.g., blood or cerebrospinal fluid or, less commonly, joint, pleural, or pericardial
fluid).