Micro: Rheumatic Fever Flashcards
Bug that causes rheumatic fever.
Strep pyogenes
How is a rapid strep test interpreted?
If it is positive: the physician is cleared to start tx.
If negative: doesn’t rule out S. pyogenes and the next step is throat culture.
What are the lab tests for S. pyogenes?
Gram (+) cocci Anaerobic Beta-hemolytic Bacitracin sensitive PYR (+)
Presentation of Strep pyogenes infection and virulence factor that causes it.
Strawberry tongue, sandpaper rash, sore throat, FEVER, arthritis.
Pyrogenic Exotoxin
Test to determine a long-term S. pyogenes infection.
ASO titer
Virulence factor that causes Rheumatic Fever.
M-protein
results in massive IgG immune response
How does the M protein cause heart damage in rheumatic fever?
The M protein shares the same Ags as cardiac myosin, sarcolemma, synovium, articular cartilage.
What is the Jones Criteria and how is it interpreted?
Dx for Rheumatic Fever
1. Must have evidence of Group A Beta-Hemolytic Strep Infection by culture or ASO titer
- Must fit 2 major manifestations OR 1 major and two minor
What are the 5 major clinical manifestations for the Jones criteria?
- Carditis
- Polyarthritis
- Chorea
- Erythema Marginatum
- Subcutaneous Nodules
When would mitral and aortic stenosis murmurs be heard?
During Chronic Rheumatic valvular disease
not acute
What are the 3 types of murmurs heard in acute rheumatic valve disease?
- High-pitched blowing holosystolic apical murmur of mitral regurgitation
- Low-pitched apical mid-diastolic flow murmur
- High-pitched decrescendo diastolic murmur of aortic regurgitation
How can Rheumatic Fever lead to Tourette syndrome?
Hypothesis is that Abs cross react with proteins in the basal ganglia. Also thought to be the cause of Sydenham Chorea
What are aschoff bodies?
Microscopic Characteristics of subcutaneous nodules seen in Rhuematic Fever.
