Denmark’s chlamydia rate among young people dropped sharply in 2024, with cases falling from 35,687 in 2022 to 24,279. But experts warn the low testing rate among young men may be hiding a much larger problem.
After years of record highs, chlamydia cases among Danish youth have finally started to fall. That sounds like good news. And it is. But the story is more complicated than the headline suggests.
The data comes from Statens Serum Institut and was analyzed by Sex & Samfund. In 2024, Denmark recorded the lowest number of chlamydia cases in a decade across all age groups. For those aged 15 to 29, the drop was significant. Denmark is not alone. Similar declines appeared in England, Finland, Ireland, the Netherlands, Norway, and Sweden.
Nobody knows exactly why
Here is where things get interesting. Experts from all seven countries met to discuss the trend. None could pinpoint a clear cause. The bacteria has not changed. Diagnostic methods have not gotten worse. So what happened?
One theory is behavioral change. Fewer partners. More caution. Better awareness. Another is that testing rates have simply dropped. If fewer people get tested, fewer cases show up in official statistics. That does not mean fewer people are infected. It means fewer people know they are.
Young men are not getting tested
The testing gap between young men and women is glaring. In 2024, just 8 percent of young men got tested for chlamydia. Among young women, the rate was 20.9 percent. Even more troubling: the positive test rate was 17.1 percent for men, compared to 9.5 percent for women.
That gap matters. If men test less but have higher positivity rates, the hidden reservoir of infection is likely huge. Majbrit Berlau from Sex & Samfund pointed out that many young men still believe testing involves an uncomfortable swab. It does not. A simple urine test works just fine.
I have watched this play out over the years in Denmark. Public health campaigns are good at reaching young women. They show up at their GP. They get tested during routine gynecological visits. Young men? Not so much. There is no routine touchpoint. No regular appointment. And clearly, not enough awareness that preventive health includes them too.
Condom use is still far too low
According to Sex & Samfund’s SexLiv 2025 survey, fewer than half of Danish youth used a condom the last time they had sex with a new partner. Even fewer young men said they were worried about catching an STI from a new partner.
This is baffling to me. Denmark has excellent sex education compared to many countries. Free testing is widely available. Yet condom use remains stubbornly low. It is partly cultural. Danes are pragmatic about sex. But pragmatism without precaution leads straight to an STI clinic.
Condoms remain the only protection against sexually transmitted infections during penetrative sex. Yes, HPV vaccines help with certain infections. But they do not cover chlamydia. And untreated chlamydia can cause infertility in both men and women.
A new national testing effort is rolling out
There is some good news on the policy front. In 2024, the government and several parties agreed to boost sexual health efforts. This includes expanding access to free home testing kits for chlamydia.
Sex & Samfund now offers free home tests to young people aged 15 to 29 in all 29 municipalities in Region Hovedstaden, plus Lolland and Kolding. The goal is to expand nationwide over the coming years. You order the test online at klamydiahjemmetest.dk, submit a sample at home, and get results by SMS or email.
This kind of low barrier access is exactly what Denmark does well. No appointment needed. No awkward conversation with your GP. Just a discreet test you can do on your own terms.
Regional differences tell a story
Chlamydia rates vary widely across Denmark. In 2024, Skive had the highest rate per 1,000 young people at 28 cases. Gentofte, Aalborg, and Aarhus were also high. But high rates often reflect high testing, not necessarily more risk.
This is a trap many people fall into when reading STI statistics. A municipality with high reported cases may simply be doing a better job testing its population. A municipality with low cases may have an invisible problem. Without testing, infections go undetected and untreated.
I have seen this dynamic in expat communities too. If you are not plugged into the Danish healthcare system or do not speak the language well, you might skip testing altogether. That makes sexual health education for marginalized groups even more urgent.
What comes next
The drop in chlamydia cases is real. But so is the risk of complacency. If Denmark scales back prevention efforts because the numbers look better, infections will rebound. History shows this clearly. After COVID lockdowns, cases surged when restrictions lifted.
Majbrit Berlau put it well. Denmark still has a
