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 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 less than 16 years of age.
Multiorgan 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.
Case classification
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.