Surveillance data show that STI rates continue to rise. Between 2022 and 2023, gonorrhoea cases increased by 31% and syphilis cases by 13%, while chlamydia remains the most commonly reported bacterial STI. Since 2014, gonorrhoea notifications have risen by over 300% and syphilis cases have doubled and drug-resistant gonorrhoea continues to spread. Young adults aged 20–24 are the most affected age group. Many infections are asymptomatic, increasing the risk of unknowing transmission.

To strengthen the evidence base for prevention strategies, ECDC mapped 35 sexual behaviour surveys conducted across the EU/EEA and the UK between 2019 and 2024. The review identified valuable datasets, including major repeated surveys such as the Health Behaviour in School Children (HBSC), the UK’s National Survey of Sexual Attitudes (Natsal) and Lifestyles, Sweden’s UngKAB, and the Netherlands’ Sex Under 25. Findings suggest a potential decline in condom use among young people aged 15–25.

However, the report also underlines significant challenges: inconsistent terminology, varied survey designs, and limited comparability across countries. These gaps restrict the ability to fully utilise behavioural data in shaping targeted and effective interventions.

ECDC recommends:

• Establishing standardised terminology and indicators for sexual health surveys

• Integrating core sexual behaviour questions into European health surveys

• Improving mechanisms for data sharing and comparison to build a clearer picture across Europe

Strengthening the collection and use of behavioural data is essential to better understand and address the drivers of STI transmission in Europe, the report concludes.

The full report is available here: Mapping and review: harnessing sexual behaviour survey data for the prevention of sexually transmitted infections.

The Chief Epidemiologist