| Contact interview at the clinic | Contact interview by phone | Total | |
| Index (%) | 257 (45) | 310 (55) | 567 (100) |
| Sex | |||
| Men (%) | 126 (48) | 139 (52) | 265 (47) |
| Women (%) | 131 (43) | 171 (57) | 302 (53) |
| Age, years | |||
| Mean age | 23.8 (14–50) | 24.1 (15–60) | 24.0 (14–60) |
| Mean age men | 25.3 (18–24) | 25.5 (15–54) | 25.4 (15–54) |
| Mean age women | 22.4 (14–50) | 22.9 (15–60) | 22.7 (14–60) |
| Contact tracing | |||
| ⩾12 Months back in time* (%) | 257 (100) | 308 (99) | 565 (100) |
| Contacts | 780 | 689 | 1469 |
| Contacts/index | 3.0 (1–30) | 2.3 (1–12) | 3.0 (1–30) |
| Known identity (%) | 655 (84) | 609 (88) | 1264 (86) |
*Contact interview covering a minimum of the previous 12 months.