The document discusses Group A beta-hemolytic Streptococcus infections and the use of anti-streptolysin O (ASO) titers to diagnose associated conditions. It notes that ASO titers rise within 2 weeks of infection and remain elevated for 3-6 months, and that a four-fold increase over 2-4 weeks suggests a recent streptococcal infection. Elevated ASO titers can help support diagnoses of acute rheumatic fever, post-streptococcal glomerulonephritis, and other conditions linked to previous streptococcal infections.

2. Dr.M.I.Beg
QGH

3.  Group A-beta-hemolytic Streptococcus produces
several virulent factors--- streptolysin
o,strptolysin s,streptokinase,Dnase
B,hyaluronidase
 A pt infected with GABHS produces antibodies
vs these virulent factors--- anti-streptolysin
o(ASO),anti-sterptokinse,anti-hyaluronidase,anti-
Dnase B.
 ASO titre takes 2 weeks to rise & remain
elevated for 3-6 mo.

4.  Four fold (two tube) increase in titre
demonstrated over time(2-4 weeks apart)
would suggest a recent steptococcal
infection.
 Single ASO titre >200 IU in children 5-15
yrs.

5.  A pt with fever,migratory polyarthritis +- cardiac murmer--
-to support diag. of acute rheumatic fever.
 A pt with oliguria,hematuria,HTN---post-streptococcal
GN.
 In pts suspected to have neurological syndromes driven
by a previous grp A streptococcal infection such as
Pediatric auto immune neuropsychiatric disorders
associated with streptococcal pyogenase(PANDAS) &
rheumatic chorea.
 In pts suspected to have other grp A streptococcal
infections such as scarlet fever,neonatal sepsis &
osteomyelitis.

6.  Diag. of ARF is clinical:Jone’s criteria(1
major+2 minor or 2 major criteria with supportive
evidence of streptococcal infection).
 Elevation of ASO titre in non-ARF conditions:
1) Post-streptococcal reactive arthritis(PSRA)
2) Systemic onset Juvenile idiopathic arthritis
3) SLE
4) Takayasu d/s
5) HSP
6) Periodic fever syndrome

7.  Anti-Dnase B
In ARF : ASO +ve in 80%
Anti-Dnase B +ve in 82%
ASO+Anti-Dnase B +ve in 92%
 Streptozyme test
 Lacks standarization & reproducibility
 Not reliable
 Throat swab

8. 1. Latent period shorter (1 week) in PSRA.
2. Arthritis is additive in PSRA rather than
migratory.
3. Relatively poor response to Aspirin in PSRA.
4. Arthritis persists for mean period of 2 mo in
PSRA.
5. 6% of PSRA may develop mitral valve d/s. It is
thus recommended that anti streptococcal
prophylaxis be given for 1 yr & then
discontinued if there is no evidence of cardiac
involvement.

9. Thanks for
your kind
attention