Peripartum sepsis with Group A Streptococcus

Today we saw a case of group A streptococcal bacteremia associated with peripartum sepsis and intrabdominal abscesses. This is similar to a case reviewed here (and here). NEJM case report here.

The case definition (epidemiologic) for streptococcal toxic shock syndrome (CDC) includes:

• hypotension defined by a systolic blood pressure less than or equal to 90 mm Hg for adults
  
• 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. 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.

In the context of a microbiologic diagnosis for group A streptococcus in a sterile site = confirmed STSS. Colonization of GAS or non-sterile site isolate = probable STSS.

Treatment includes supportive care, debridement of necrotic/non-viable tissues and source control , consideration of IVIG , and antibiotic therapy with beta-lactam (i.e. penicillin) with clindamycin (for its anti-ribosomal activity and effect on non-log phase growth); however, recent data suggests that exotoxin production may actually be increased if the organism is clindamycin resistant. Linezolid may be an alternative anti-ribosomal agent in this case.