Sexually transmitted diseases in the Nordic countries

The registered increase in incidence of sexually transmittable diseases is partly a question of increased case detection. Over time the national surveillance systems have improved and more people are being tested. The introduction of combined diagnostic tests, more sensitive tests, the possibility for self-administered home-testing and increased frequency of testing have possibly affected the incidence figures.

Historically, these sexually transmittable diseases were quite prevalent. However, over the past 20 years there has been a marked fall in the incidence of gonorrhea and syphilis due to better treatment in the Nordic countries. Now the figures are increasing again. Changes in sexual behavior; more unprotected sex and frequent change of sexual partners, have made us more vulnerable to these diseases. People also travel more; approximately 1 in 4 were infected abroad (ex. in Spain, Germany, USA and Thailand). It is a public health concern that gonorrhea is increasing, and that it might become resistant to the antibiotics that is normally prescribed to treat it. The first cases of antibiotic resistant gonorrhea have already been detected in Europe.

The widespread prevalence of chlamydia among young people is a public health problem. Chlamydia is an asymptomatic infection, with no or mild symptoms or signs. It is therefore likely that many infected persons are unaware that they need treatment. Untreated chlamydia infections can spread to other parts of the body and lead to long-term health problems such as pelvic inflammatory disease, infertility and increased risk of HIV.

The prevalence of chlamydia is generally higher in women than in men. That more women are diagnosed with chlamydia can partly be due to more frequent contact with the health services in relation to pregnancy and widespread testing for cervical cancer. The Danish State Serum Institute (together with Imperial college, London) is involved in testing a vaccine against chlamydia. It is early days, but if the result is a public available vaccine this will reduce the incidence rates of chlamydia in the future.

Of the Nordic countries Greenland has the highest levels of people diagnosed with chlamydia. Greenland reported chlamydia rates almost 10 times the rates reported for Denmark. The rates have, however, been dropping after 2012.

Apart from Greenland, it is women in Denmark, Iceland and Norway that have the highest rates of chlamydia compared to the other Nordic countries. And the rates have been increasing In Denmark, Norway and the Faroe Islands in later years.

Gonorrhea and syphilis affect mainly young people under 30 years. These infections are more frequent in men than in women, although there has been an increase in infections among women in the past years. Men who have sex with men (MSM) accounts for almost half of the reported cases of gonorrhea.

The highest number or cases are seen among Greenlandic women. Unlike the other Nordic countries, Greenland has as almost equally high number of cases among women as among men. The incidence of gonorrhea is significantly lower in the other Nordic countries. However, notifications of gonorrhea are increasing in both Denmark, Iceland, Norway, Sweden. The Faroe Islands has relatively few cases.

Syphilis is not very common in the Nordic countries. In Greenland there were no reported cases in 2010. However, the number has risen dramatically in recent years. Apart from Greenland, Iceland has the highest incidence rate, and the rate has increased significantly in later years. Iceland has three times the incidence rates of Norway and Sweden. Most cases are detected among young men. The incidence rate has also been increasing in Denmark in the past ten years, although the rates have dropped somewhat in later years. In Norway the number of cases has been increasing slowly year by year. It is a lower detection of syphilis in Finland compared to other Nordic countries. In recent years there are no notified cases of syphilis in the Faroe Islands.

European Centre for Disease Prevention and Control (ecdc)

Folkehelseinstituttet (NIPH; Norwegian Instiute of Public Health, MSIS), Norway

Embætti Landslæknis, Directorate of Health, Iceland. EPI-ICE, Chief Epidemiologist for Iceland, Vol. 12. Issue 3, October 2019.

Statens serum Institutt, SSI, Denmark. MiBa; Den Danske Mikrobiologidatabase.

Landslægeembedet, Greenland

Folkehälsomyndigheten, The Public Health Agency of Sweden.

Institut for Hälsa og Velfärd, THL. Finland