In 2019, the number of sexually transmitted diseases increased significantly in Finland, according to National Institute for Health and Welfare (THL) data.


Chlamydia infection is the most common sexually transmitted disease in Finland. Almost 16,200 chlamydia infections were diagnosed in 2019, which is more than 1,000 more than in 2018. This is the largest number ever reported to the National Infectious Diseases Register during one year. The infections focus on young adults: almost 80% were diagnosed in 15–29-year-olds.

Gonorrhea and syphilis infections also increased last year. More than 600 syphilis infections were diagnosed, which is about 100 more than in the previous year. Almost 250 gonorrhea infections were diagnosed, which is about 60 more cases than in 2018.

‘The number of sexually transmitted diseases has been on the rise for several years. It is possible, that testing activity has increased, and attempts have been made to make it easier in the municipalities, for example, by means of remote testing. Condom is the only method of contraception that also protects against sexually transmitted diseases’, says Tuula Hannila-Handelberg, Chief Physician at the Finnish Institute for Health and Welfare.