Syphilis 2022

Syphilis 2022

The present report on notified syphilis cases in 2022 only comprises data from the Notification System for Infectious Diseases (NSID).

In 2022, 676 syphilis cases were notified to the NSID, Department of Infectious Disease Epidemiology and Prevention, Statens Serum Institut; 606 cases among men and 70 cases among women.

The 676 cases occurred in 668 persons as 9 persons were notified with more than one case in the course of the year.

The median age was 41 years for men (range 0-77 years) and 38 years for women (range 17-60 years), Table 1.


As in previous years, the majority of the patients resided in the Copenhagen area, Table 2.


The decline registered in 2018, when the number of notified syphilis cases was 311, has been replaced by an increase since 2019. The increase was observed mainly among men who have sex with men (MSM), but this group experienced a decline from 2021 to 2022, Figure 1.


Congenital syphilis and syphilis in pregnant women

Among 70 cases of syphilis detected in women in 2022, eight (11%) were found in pregnant women, four of whom were Danish born. In 2022, the pregnancy screening efforts confirmed a total of 12 female syphilis cases. Thus, four pregnant women with syphilis (33%) had not been notified to the NSID.

One case of congenital syphilis was notified in 2022; in a child who was not born in Denmark, but who received treatment here.


Sexual orientation

Among the 606 notified men, 105 (17%) were notified as having become infected by heterosexual contact (HTX), 484 (80%) by MSM contact and for 16 (3%), the mode of infection was not stated. A total of 70 women were notified, 67 infected by HTX, including one transsexual woman and three for whom the mode of transmission was not stated. In 2022, women comprised 10% of all notifications, Figure 1.

Origin and country of infection

Among the 676 notified cases, 466 (69%) were Danish and 210 (31%) were immigrants, tourists, etc.

The country of transmission was stated for 626 (93%) of those notified; 568 men and 58 women. A total of 509 men (84%) and 53 women (76%) had become infected in Denmark. Among HTX-infected men for whom the country of transmission was stated, 84 of 102 (82%) had become infected in Denmark, whereas this was the case for 417 of 456 (91%) of the MSM.

Syphilis and HIV

Information about HIV status was available for 604 (89%); 547 men (90%) and 57 women (81%).Among the 447 MSM for whom HIV status was stated, 113 (25%) were HIV positives. All were previously known to be HIV positives. Thus, in 2022, no MSM received their HIV diagnosis when receiving their syphilis diagnosis.

A total of eight HTX infected people (men as well as women, including a transsexual) , were notified as HIV positives, among whom around half had newly detected HIV. The newly detected cases were men who had become infected by sex workers abroad.

(M. Wessman, S. Cowan, Department of Infectious Epidemiology and Prevention)

This report is also described in EPI-NEWS no. 51a/2023.