Table 3.
Prevalence of latent yaws in subgroups determined by age
| Time (month) |
Children aged 1 – 5 years | Children aged 6 – 15 years | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| No. of children tested |
All Cases of Latent Yaws* | High-titre Latent Yaws† | No. of children tested |
All Cases of Latent Yaws* | High-titre Latent Yaws† | |||||
| no. of children (%) |
Adjusted prevalence ratio (95%CI)ठ|
no. of children (%) |
Adjusted prevalence ratio (95%CI)ঠ|
no. of children (%) |
Adjusted prevalence ratio (95%CI)‡ ∥∥∥∥ |
no. of children (%) |
Adjusted prevalence ratio (95%CI)‡**∥ |
|||
| Baseline | 117 | 26 (22·2) | 1 | 16 (13·7) | 1 | 874 | 299 (34·2) | 1 | 165 (18·9) | 1 |
| 6 mo | 77 | 10 (13·0) | 0·58 (0·20; 1·74) | 6 (7·8) | 0·57 (0·15; 2·19) | 797 | 251 (31·5) | 0·92 (0·55; 1·53) | 117 (14·7) | 0·78 (0·40; 1·53) |
| 12 mo | 114 | 6 (5·3) | 0·24 (0·09; 0·63) | 1 (0·9) | 0·06 (0·01; 0·48) | 796 | 143 (18·0) | 0·53 (0·35; 0·79) | 58 (7·3) | 0·39 (0·19; 0·77) |
| 18 mo | 81 | 9 (11·1) | 0·50 (0·22; 1·12) | 1 (1·2) | 0·09 (0·02; 0·52) | 462 | 129 (27·9) | 0·82 (0·55; 1·22) | 50 (10·8) | 0·57 (0·34; 0·98) |
| 24 mo | 69 | 6 (8·7) | 0·39 (0·17; 0·88) | 1 (1·4) | 0·11 (0·01; 0·75) | 445 | 113 (25·4) | 0·74 (0·48; 1·15) | 24 (5·4) | 0·29 (0·16; 0·52) |
| 30 mo | 65 | 4 (6·2) | 0·28 (0·10; 0·79) | 0 (0·0) | -- | 416 | 136 (32·7) | 0·96 (0·62; 1·48) | 33 (7·9) | 0·42 (0·18; 0·97) |
| 36 mo | 66 | 3 (4·5) | 0·20 (0·05; 0·80) | 1 (1·5) | 0·11 (0·02; 0·78) | 470 | 130 (27·7) | 0·81 (0·47; 1·40) | 22 (4·7) | 0·25 (0·08; 0·81) |
| 42mo. | 68 | 6 (8·8) | 0·40 (0·17; 0·94) | 0 (0·0) | -- | 422 | 84 (19·9) | 0·58 (0·37; 0·91) | 28 (6·6) | 0·35 (0·20; 0·62) |
*
The analysis included all seropositive children with a reactive TPHA and RPR titre of at least 1:2.
†
The analysis included children with a reactive TPHA and RPR titre of at least 1:16.
‡
The adjusted prevalence ratio was calculated with the use of the cluster option of a log-binomial regression model. The baseline prevalence is the reference value.
§
P = 0·0165 for the significance of the model overall.
¶
P = 0·0014 for the significance of the model overall
∥
P = 0·0024 for the significance of the model overall
**
P = 0·0002 for the significance of the model overall.
Baseline, 6 and 12 month data were previously published (Ref. 7) and are included here for comparison to later time points