HIV and syphilis in Denmark 2025 – status, trends, and why testing is still crucial
In Denmark in 2025, the picture for both HIV and syphilis is twofold: treatment and prevention have improved, but a significant proportion of infections are still detected late, and syphilis remains at a high level compared with the rest of Europe. This makes broad, accessible and target-group-oriented testing continuously central – especially for clinics, municipal services and NGOs.
HIV – fewer new infections, but too many are diagnosed late
In 2023, 227 HIV cases were reported in Denmark. 110 were diagnosed in Denmark, while 117 were already known HIV-positive from abroad, including a larger group of displaced people from Ukraine. The figures highlight that migration affects the case mix, but does not change the need for systematic, early testing in Denmark.
A persistent problem is “late testing”: among newly diagnosed individuals, the proportion of people who receive their diagnosis late in the course of infection remains high – particularly among those infected heterosexually, but also among MSM. Late testing increases the risk of further transmission and reduces the opportunities for early treatment.
Syphilis – high prevalence, recurrent infections and broader target groups
Syphilis has increased significantly over the past decade. In 2023, 649 cases were reported in 638 individuals. The majority were men; the median age was 41 years for men and 37 years for women. Recurrent infections were common, indicating ongoing transmission in social networks.
Within the EU/EEA, Denmark is among the countries with high syphilis rates; the regional incidence was 9.9 per 100,000 in 2023, driven especially by transmission among men aged 25–34 years. Denmark is at around 11 per 100,000, which calls for continued vigilance – also outside major urban centres.
Why testing is still a core component
Even with PrEP, TasP and strengthened prevention strategies, early diagnosis is crucial to breaking chains of transmission. The high proportion of late HIV testers and high syphilis rates in the European context show that relying solely on treatment and behaviour change is not enough; testing must remain widely accessible, frequent in relevant groups and organised with a low threshold for access in both clinical and community-based settings.