Background
Routine surveillance of sexually transmitted infections (STIs) organised by the European Centre for Disease Prevention and Control is impacted by variations across countries in national testing practices and surveillance systems characteristics. To better describe the epidemiology of the four curable STIs (chlamydia, gonorrhoea, trichomoniasis, syphilis) in Europe, we conducted a systematic review of prevalence estimates for the general population and populations of special interest.

Methods
From seven databases and a grey literature search, we systematically retrieved prevalence studies from European countries published between January 2012 and February 2024 with data for the general population, suitable proxy populations, men who have sex with men (MSM), sex workers, and/or people who inject drugs (PWID). Study quality was assessed using the Joanna Briggs Institute checklist and pooled prevalence estimates were calculated using random effects models.

Results
We included 97 studies from 25 countries. Prevalence estimates in women are 2.81% (95%CI 1.71–3.91) for chlamydia, 0.29% (95%CI 0.05–0.54) for gonorrhoea, 0.69% (95%CI 0.41–0.98) for trichomoniasis, and 0.16% (95%CI 0.02–0.30) for syphilis. In men, prevalence estimates are 2.67% (95%CI 0.65–4.69) for chlamydia, 0.27% (95%CI 0.00–0.64) for gonorrhoea, and 0.13% (95%CI 0.00–0.34) for trichomoniasis. Prevalence estimates varied for young people, women in antenatal care, MSM, sex workers and PWID. However, interpretability of pooled results is limited by low number of estimates, heterogeneity in study design, and different sampling timeframes.

Conclusions
Variations in STI prevalence across populations in Europe warrant targeted public health actions. Recent and high-quality prevalence estimates are rare and unevenly available across European countries. Enhancing data collection efforts at the national level is needed to track progress towards the elimination of STIs as a public health concern.