| Age group (yrs) | No. of samples (%) | Number of isolates (%) |
| 15 - 24 | 100 (33.3) | 27 (33.7) |
| 25 - 34 | 157 (52.3) | 45 (56.3) |
| 35 - 44 | 43 (14.3) | 8 (10.0) |
| Total | 300 (100) | 80 (100) |