- In 2022, there is an increase globally of invasive Group A Streptococcus and Scarlet Fever
- Group A Streptococcus results in 700 million infections and complicated by 500,000 deaths each year worldwide
- Post-streptococcal complications have become uncommon in the United States
- Complications are more common in Sub-Sahara Africa, India, Australia, New Zealand
- General
- Anaerobic Gram Positive Cocci
- Beta-hemolytic Streptococcus (induces complete RBC Hemolysis in its vicinity)
- Lancefield Group A (C CarbohydrateAntigen) in Bacterial cell wall
- Pyogenes is derived from greek "pus forming"
- Humans are only reservoir
- Beta Hemolysis Factors
- Virulence Factors
- Hyaluronidase
- Anti-C5a Peptidase
- DNAase
- Streptokinase
- Activates plasmin, triggering Fibrinolysis (nearly identical to staphylokinase)
- Streptokinase is extracted from Group C Strep to be used in MI and Stroke (prior to tPA, TNK)
- Lipoteichoic Acid
- Aids in Bacterial adherence
- M Protein
- Inhibits Complement Activation
- Inhibits Phagocytosis, and allows for rapid subcutaneous spread (e.g. Necrotizing Fasciitis)
- M Protein also provides an Antigenic target for immune response to clear infection
- Toxins
- Pyrogenic exotoxin (erythrogenic toxin)
- Expressed by strains that cause Scarlet Fever
- Toxic Shock Syndrome Toxin (TSST)
- Exotoxins hyperstimulate T-Cell response with high Cytokine release (Toxic Shock Syndrome)
- Similar to Staphylococcal exotoxin
- Pyrogenic exotoxin (erythrogenic toxin)
-
Antibiotic management of Streptococcal Pharyngitis and decreases Rheumatic Fever risk
- However, does not prevent Post-Streptococcal Glomerulonephritis
- Autoimmune complications arise from Antibody formation against streptococcal M Protein
- Immune complex deposition in Post-Streptococcal Glomerulonephritis
- Antibody directed reaction in Acute Rheumatic Fever
- Autoantibody cross-reaction to Basal Ganglia in Sydenham Chorea
- Infections Caused by Group A Beta Hemolytic Streptococcus
- Systemic Infections
- Streptococcal Bacteremia (Age under 3 years)
- Toxic Shock Syndrome
- Bacterial Meningitis
- Subacute Bacterial Endocarditis (SBE)
- Respiratory Infections
- Skin Infections
-
Poststreptococcal Reactive Arthritis
- Onset 1-2 weeks after streptococcal infection
- Severe and prolonged Arthritis
- Contrast with Rheumatic Fever associated Arthritis
- Poststreptococcal Glomerulonephritis
- Childhood Acute Neuropsychiatric Symptoms (or PANDAS)
- Guttate Psoriasis
- Sydenham's Chorea
- Rheumatic Fever
- Henoch Schonlein Purpura