| Age group | No. of specimens | E. coli positive (%) | χ2 | P-value |
| 15 - 19 | 3 (4) | 0 |
|
|
| 20 - 19 | 46 (58.9) | 3 (6.5) | 2.734 | 0.431 |
| 30 - 39 | 25 (32.1) | 4 (16) |
|
|
| 40 - 49 | 4 (5) | 0 |
|
|
| Total | 78 | 7 |
|
|