Wider availability of free condoms could help reduce infections, a THL research professor suggests.File photo of a home test kit for STIs. Image: Pohjanmaan hyvinvointialueYle News13:13Over 12,000 cases of chlamydia were recorded in Finland last year, making it the country's most common sexually transmitted infection (STI).The Finnish Institute for Health and Welfare THL's infectious disease register also recorded around 2,100 cases of gonorrhoea and 329 cases of syphilis in 2025.THL Research Professor Mika Gissler noted that the closure of Finland's eastern border with Russia in December 2023 has affected infection patterns."Even if case numbers are relatively low, anyone can contract a sexually transmitted infection if they don't take precautions," Gissler said. Image: Jorge González / Yle"Previously, syphilis and gonorrhoea infections, particularly those linked to paid sex, came across the border from Russia. Now that route has been closed in eastern Finland," Gissler said.He added that some people are instead acquiring infections abroad, with men in particular bringing sexually transmitted diseases back from destinations including Thailand.Most STIs are diagnosed in young adults, although cases are also reported among older people.Gissler said he is surprised infections remain so common despite good knowledge about sexual health practices among young people and low teenage pregnancy rates. He suggested that while free contraception is widely available, it is often focused on preventing pregnancy rather than sexually transmitted infections.He added that wider availability of free condoms could help reduce infections.Untreated STIs can have serious health consequences. Syphilis can be life-threatening if left untreated, while gonorrhoea and chlamydia can lead to fertility problems.