Prevalence and determinants of sexually transmitted infections in women at risk undergoing abortion in a Swiss primary care setting.

Background: Specific prevalence data are needed to assess the burden of sexually transmitted infections (STIs) in specific settings where data are scant, such as women seeking early termination of pregnancy (TOP). We aimed to investigate the prevalence of STIs and its determinants in women at risk (e. g. pathological cervical swab) undergoing TOP in a primary care setting in Switzerland.
Methods: Cross-sectional study of 620 women seeking abortion counselling at a general practice in Zurich, Switzerland. Patients' characteristics were assessed and in case of pathological cervical swab a PCR-based screening for Chlamydia trachomatis (CT), Mycoplasma genitalium (MG) and Neisseria gonorrhoeae (NG) was initiated to estimate STI prevalence. Bi-and multivariable analysis were used to investigate STI determinants.
Results: 585 out of the 620 women presenting for counselling resulted in TOP. 581 (93,7%) cervical specimens were available with 272 having pathological signs (46,8%), thus were considered at risk for STIs. In 192 screened samples 28 STIs (14,6%) (95% CI: 10,3-20,3%) were detected, predominantly CT (17 cases) followed by MG (9 cases) and NG (2 cases). Compared to non-immigrants, immigrants were more likely to have a STI (adjusted OR 2,63; p=0,037) Non-screened women were significantly more often self-payers (31,3%) compared to screened women (8,3%) (p<0,001).
Conclusion: We found a high STI prevalence in women presenting for TOP in a Swiss primary care setting. Women with a migration background seemed to be a vulnerable subgroup. Public health efforts are needed to implement cost-effective screening and case management programmes in this population at risk for STIs.