Sexually transmitted infections in Europe reached record levels in 2024, with new ECDC data showing sharp increases in gonorrhoea and syphilis across EU and EEA countries. The European Centre for Disease Prevention and Control said the trend reflects gaps in testing and prevention, while Denmark’s figures show a mixed picture: chlamydia is falling, but gonorrhoea and syphilis remain higher than in 2020.
Gonorrhoea and syphilis are driving Europe’s STI surge
The latest surveillance data from the EU health agency point to a clear shift in Europe’s sexually transmitted infections landscape. Chlamydia remains the most frequently reported bacterial STI, with 213,443 confirmed cases reported by 27 EU/EEA countries in 2024. But the most significant increases concern gonorrhoea and syphilis.
ECDC reported 106,331 confirmed cases of gonorrhoea in 2024 across 28 EU/EEA countries. That is the highest level recorded since European STI surveillance began in 2009 and represents a 303% increase in the notification rate since 2015. Syphilis also reached its highest level in the past decade, with 45,577 confirmed cases reported by 29 EU/EEA member states.
The figures do not necessarily mean that transmission is increasing at the same pace everywhere. National testing systems, reporting rules and access to sexual health services vary widely across Europe. Still, ECDC’s warning is direct: without targeted action, the current trend is likely to continue.
Men who have sex with men remain most affected, but syphilis is widening
The rise is still concentrated in specific groups. ECDC data show that men who have sex with men accounted for 62% of gonorrhoea cases with known transmission category in 2024 and 69% of syphilis cases with known transmission category. This confirms that prevention, testing and treatment services aimed at high-risk groups remain central to the public health response.
At the same time, the data also show a wider spread of syphilis beyond key populations. Since 2021, ECDC has recorded sustained increases among heterosexual men and women across adult age groups. The agency is particularly concerned about women of reproductive age, because untreated syphilis during pregnancy can be transmitted to the child.
This is one of the most sensitive findings in the new surveillance update. ECDC reported that congenital syphilis cases in Europe nearly doubled in 2024. Although the absolute numbers remain limited compared with other STIs, the increase signals a gap in prevention, pregnancy screening or access to timely treatment in parts of Europe.
Testing access has become a European prevention challenge
The public health message is not limited to individual behaviour. ECDC is calling for easier access to testing and treatment, better prevention strategies and stronger surveillance. Condom use with new or multiple partners remains a core recommendation, but the agency also stresses the importance of testing when symptoms appear or after possible exposure.
Gonorrhoea can cause burning during urination, pain and discharge from the urethra, vagina or rectum, but it can also be asymptomatic. Chlamydia is also frequently asymptomatic, which makes regular testing important in sexually active groups at higher risk. Untreated infections may lead to complications, including infertility in some cases.
The rise in gonorrhoea also raises a longer-term concern: antimicrobial resistance. Gonorrhoea is treatable with antibiotics, but resistance patterns require continuous monitoring. For health systems, the issue is therefore not only the number of infections, but whether testing, treatment and partner notification can keep pace with transmission.
Denmark reports fewer chlamydia cases but higher gonorrhoea and syphilis than in 2020
Denmark’s data show a more nuanced pattern than the overall European trend. According to Danish figures cited in the latest reporting, chlamydia cases fell from 34,681 in 2020 to 29,946 in 2024, after reaching 37,111 in 2023. Statens Serum Institut (SSI) has also reported a fall in chlamydia cases and testing episodes from 2023 to 2024.
Gonorrhoea is different. Danish cases rose from 3,550 in 2020 to just over 5,000 in 2024. SSI’s annual report registered 5,112 gonorrhoea cases in 2024, a small decrease from 2023 but still at a higher level than before the sharp increase observed in 2022. Men accounted for 71% of registered gonorrhoea episodes in Denmark in 2024.
Syphilis also remains higher than in 2020. Denmark reported 628 syphilis cases in 2024, compared with 445 in 2020. SSI data show that most notified cases were among men, especially men who have sex with men, but the institute also reported 15 syphilis detections among pregnant women and one case of congenital syphilis in 2024.
Home testing in Denmark points to a broader shift in access
One Danish response has been to make testing easier for some groups. Region Zealand (Region Sjælland) has introduced a model allowing young people who suspect infection with chlamydia, gonorrhoea or trichomonas to order a free home test through the selftest.dk platform, rather than first going through a doctor.
The initiative reflects a broader European challenge. If many infections have mild symptoms or no symptoms at all, prevention depends not only on awareness campaigns but also on low-threshold access to testing. Digital booking, home testing and targeted outreach can reduce barriers, especially for young people and groups less likely to contact healthcare services early.
For the Nordic countries and the EU/EEA, the new data point to the same conclusion: sexually transmitted infections are no longer a marginal public health issue. The most effective response will depend on combining prevention, accessible testing, timely treatment and surveillance that can detect changes before they become harder to control.
