When people think of sexually transmitted infections (STIs), they often picture young adults—but the reality in clubs, dark rooms, and dating apps tells a different story. An analysis of about 84,000 reports to Germany’s Robert Koch Institute (RKI) from 2019 through 2025, conducted by the adult site Erobella, shows that the average age of STI diagnoses in Germany has been climbing steadily and is shifting notably toward those over 50.
The median age for syphilis diagnoses is now 41. Almost one in three new diagnoses involve people over 50. The share of individuals aged 60 to 64 has doubled since 2019. Syphilis typically presents as a skin ulcer.
HIV is also increasingly affecting older people: most new HIV diagnoses fall in the 35- to 39-year-old bracket. An important caveat for interpretation: HIV is often not detected until years after the actual transmission, so the true age of infection is usually younger.
Gonorrhea (the clap), which often progresses with few symptoms, remains more common in younger cohorts. The most affected group is 25- to 29-year-olds, with a median age of 32. Because nationwide data only capture resistant strains, these figures reflect only the tip of the iceberg. Since 2001 there has been no nationwide mandatory reporting for gonorrhea. A new reporting obligation approved in 2022 has not yet been implemented because the electronic reporting system is missing.
Case numbers versus real per-capita risk
That more cases are being reported in older age groups is partly a result of demographics: the baby boomer generation is simply larger in number. When you translate the figures into risk per 100,000 residents, the highest likelihood of infection with these three STIs still falls between ages 25 and 39.
The “PrEP Effect”: Those who test, find
The analysis highlights a factor that directly affects gay men: people who use HIV pre-exposure prophylaxis (PrEP) undergo routine STI screening every three months. Asymptomatic infections—especially syphilis and gonorrhea in the throat or rectum—that might otherwise go unnoticed are detected far more quickly within the community. So an uptick in reported cases is not automatically a sign of riskier behavior, but often the result of effective prevention and testing networks. According to the Robert Koch Institute, the share of men who have sex with men on PrEP ranges from 97 to 99 percent.
The findings validate the approach of AIDS prevention organizations that are increasingly directing outreach toward older adults. They advocate testing at any age, because syphilis and gonorrhea are usually treatable with antibiotics, though rising resistance—particularly for gonorrhea—can pose bigger challenges. Moreover, HIV under treatment is not transmissible (see TheColu.mn interview with expert Holger Wicht).
