Table 3. Antistreptolysin O titer in age based sub-groups.
| Groups reclassified According | <200 IU/mL | 200 IU/mL | 400 IU/mL | 800 IU/ml | 1200 IU/mL | 1600 IU/mL | 1800 IU/mL | ULN (80th percentile) |
|---|---|---|---|---|---|---|---|---|
| Controls | ||||||||
| ≤5 years=12 | 9(4.5%) | 3(1.5%) | 200 | |||||
| 6-10 yrs=114 | 53(26.5%) | 44(22.0%) | 16(8.0%) | 1(0.5%) | 200 | |||
| >10yrs=74 | 8(4.0%) | 15(7.5%) | 43(21.5%) | 8(4.0%) | 400 | |||
| ARF (1st attack) | ||||||||
| 6-10 yrs=15 | 1(5.0%) | 8(40.0%) | 3(15.0%) | 3(15.0%) | ||||
| >10 yrs=5 | 1(5.0%) | 1(5.0%) | 3(15.0%) | |||||
| Recurrent ARF | ||||||||
| 6-10 yrs=27 | 5(12.5%) | 12(30.0%) | 8(20%) | 2(5.0%) | ||||
| >10 yrs=13 | 6 (15.0%) | 6(15%) | 1 (2.5%) | |||||
| Chronic RHD | ||||||||
| ≤5 yrs=3 | 3(3.0%) | <200 | ||||||
| 6-10 yrs=61 | 38(38.0%) | 20(20.0%) | 3(3%) | 200 | ||||
| >10 yrs=36 | 13(13.0%) | 10(10.0%) | 10(10%) | 3(3%) | 400 | |||
| Acute follicular tonsillitis | ||||||||
| ≤5 yrs=14 | 11(11%) | 3(3%) | ||||||
| 6-10 yrs=64 | 25(25%) | 26(26%) | 13(13%) | |||||
| >10 yrs=22 | 4(4%) | 18(18%) | ||||||
| H of Recurrent F tonsillitis | ||||||||
| ≤5 yrs=21 | 9(4.5%) | 5(2.5%) | 7(3.5%) | 1600 | ||||
| 6-10 yrs=134 | 2(1%) | 44(22.0%) | 46(23.0%) | 42(21.0%) | 1600 | |||
| >10 yrs=45 | 10(5.0%) | 16(8.0%) | 19(9.5%) | 1600 | ||||
ARF, acute rheumatic fever; RHD, rheumatic heart disease; H of recurrent F tonsillitis, history of recurrent follicular tonsillitis; ULN, upper limit of normal; yrs, years ULN (80th percentile).