Prevalence of STIs and people's satisfaction in a general population STI testing site in Bern, Switzerland

Access to affordable STI testing for asymptomatic persons is important to reduce STI transmission. Our testing site offers easily accessible and affordable STI testing for the general population irrespective of symptoms. Here we report STI prevalence and motivational factors of attendance.

Between 2017 and 2019, all participants at our STI testing site at the University Hospital Bern, Switzerland, were interviewed with a computer-based self-completion questionnaire. Pooled (oral, genital and anal) swabs were tested for Chlamydia trachomatis, Neisseria gonorrhoeae and blood samples for syphilis and HIV. People's motivational factors to attend were assessed using a standardised questionnaire.

5402 individuals between 17 and 82 (median 33.5) years were included. Of those, 2550 (47.2%) were between 25 and 34 years old and 3133 were heterosexual (58%), with rising attendance over the years. One-third attended because of a new sexual relationship, and one-third reported condomless sex. Among all individuals, we found 191 (3.8%) new chlamydia infections (89/191 in females and 101/191 in males) and 54 (1.1%) gonorrhoea infections (44/54 in males). In addition, 52/5125 tested individuals (0.8%) had syphilis requiring treatment.The number of sexual partners, previous bacterial STIs and condomless sex were associated with having an STI. Four heterosexual individuals were newly diagnosed with HIV. People rated a low threshold offer (through online booking or telephone) and personal counselling as most important factors to attend the service.

We found many asymptomatic bacterial STIs requiring treatment. Offering easily accessible STI testing and counselling proved successful as shown by increasing rates of attendance and high levels of satisfaction.