A sharp increase in syphilis cases in Europe is hitting hardest among MSM and has been linked to the use of PrEP drugs and an increase in risky sexual behavior.
After dipping slightly a decade ago, the number of reported syphilis cases in Europe reached the highest case count yet in 2017, according to a new report from the European Centre for Disease Prevention and Control (ECDC).
Recent studies have noted increases in the incidence of certain sexually transmitted infections (STIs), such as chlamydia, gonorrhea, and syphilis. The trend is particularly concerning among men who have sex with men (MSM) taking pre-exposure prophylaxis (PrEP) to prevent HIV infection and who engage in risky sexual behavior such has having sex without condoms. The troubling report released by the ECDC on syphilis and congenital syphilis in Europe reviews epidemiological trends from 2007 to 2018 and notes that syphilis notifications in Europe have increased by 70% since 2010.
Following a period of decline in reported syphilis cases in Europe from 2007 to 2010, which saw as few as 19,000 cases documented in a year, the new report notes that notification rates in European Union (EU) and European Economic Area (EEA) countries reached an all-time high in 2017 with more than 33,000 reported syphilis cases. “Since 2010, syphilis notification rates in the EU/EEA have been on the increase, but in recent years this trend seems to accelerate, predominantly among men having sex with men (MSM),” notes that report. “Similar trends have been observed in high-income countries outside the EU/EEA.”
The new report draws on an analysis of EU/EEA surveillance data collected from 2007 to 2017 on syphilis and congenital syphilis, a 2019 survey of EU/EEA member states on recent syphilis trends and changes in surveillance, and a literature review to identify trends, recent outbreaks, and drivers of the growing syphilis epidemic. Overall, from 2010 to 2017, the syphilis notification rate among men doubled and decreased by 14% among women. MSM were the most affected population, with increasing STI rates and outbreaks linked to factors such as a general increase in the number of sex partners in HIV-negative MSM and the use of social networking and dating sites. In addition, most of the syphilis outbreaks and case clusters in the last 10 years predominantly affected MSM and occurred in urban areas.
“Lower case numbers were reported among heterosexual men and women, but in some countries, rates among heterosexual populations are on the increase,” notes the report. Factors associated with increased syphilis incidence among heterosexual populations include unprotected sex, multiple sex partners, substance use, history of incarceration, sex work, previous STIs, and several social vulnerabilities.
There were 15 countries reporting an increase in syphilis notifications of more than 15% from 2010 to 2017, with Iceland reporting the largest increase of 876%. The other large increases were in Ireland (224%), the United Kingdom (153%), Germany (144%), and Malta (123%). During the same period, Estonia and Romania reported a decline of at least 50%.
"There is a clear relationship between sexual risk behavior and the risk of syphilis and other sexually transmitted diseases," Andrew Amato-Gauci, head of the ECDC program on HIV, STI, and viral hepatitis, said in a recent statement. "To reverse this trend, we need to encourage people to use condoms consistently with new and casual partners. Regular tests for syphilis and other sexually transmitted infections should also be part of the parcel, especially if there has been a risk of infection."