Rising rates of sexually transmitted infections across Europe

The latest ECDC reports on chlamydia, gonorrhoea, and lymphogranuloma venereum (LGV) highlight a sharp increase in reported cases of these STIs across 27 European Union/European Economic Area (EU/EEA) countries, and collectively reveal a dynamic and challenging landscape. This rise in numbers is similar to the increase in syphilis cases previously reported by ECDC and illustrates a decade-long trend of growing STI rates across Europe despite a dip in numbers during the COVID-19 pandemic, likely due to changes in access to testing and reduced social mixing.

The number of reported gonorrhoea cases has continued to increase, as they had done before the COVID-19 pandemic. In 2021 alone, there were 46 728 confirmed cases of gonorrhoea, surpassing pre-pandemic levels. Though the data reveals substantial variations across the EU/EEA, men who have sex with men (MSM) accounted for more than half of reported cases. Amid the rise in cases, concerns about antimicrobial resistance (AMR) are particularly pronounced in the context of gonorrhoea. The European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP) reports increasing resistance to two particular antibiotics, azithromycin and ciprofloxacin, emphasising the need for vigilant monitoring and robust response strategies.

The report on chlamydia reveals a similar picture with increases from 2012 to 2019, a decline in 2020 likely due to the impact of the pandemic followed by an increase again in 2021. Rates continue to be highest among young adult heterosexual women. Gender disparities in chlamydia testing, with young women receiving the most testing, means chlamydia may be underdiagnosed among men. 

ECDC’s assessment of LGV indicates a concerning rise in reported cases. The infection, caused by Chlamydia trachomatis, presents unique challenges due to its potential long-lasting complications. The report underscores the importance of targeted prevention strategies and enhanced surveillance to curb the spread of LGV, as increasing proportions of cases are among HIV-negative MSM. Case finding should also focus on this group, particularly among those eligible for, or on, HIV pre-exposure prophylaxis (PrEP). The number of cases described is likely to be an underestimation as many countries do not have national surveillance systems for LGV and confirmation of infection through molecular diagnostics is not widely available.

The escalating numbers of reported STIs pose a significant public health challenge. ECDC recommends the following actions:

• Urgent Strengthening of Prevention Activities: Enhanced prevention activities are crucial, focusing on increased testing, targeted messaging, and tailored interventions for specific risk groups. Social media and dating apps should be considered for prevention campaigns, in addition to traditional approaches.

• AMR Monitoring: Ongoing monitoring of antimicrobial resistance is imperative to inform treatment strategies and address emerging challenges.

Recent reports on syphilis and congenital syphilis show a steadily increasing trend despite a temporary dip in 2020. In 2021, 25 270 confirmed syphilis cases were reported in 28 EU/EEA Member States, which represents an increase over 2020 when cases had declined for the first time in 8 years. Notably, MSM bear a disproportionate burden, constituting 77% of cases. In 2021, around one-third of MSM with syphilis were HIV positive. While there was a dip in cases among MSM between 2020 and 2021 and a minor upswing in male heterosexual cases, women exhibited consistently low rates of syphilis infections in 2021. 

The total number of congenital syphilis notifications in 22 EU/EEA countries that consistently reported data for 2012-2021, showed a peak in 2013 followed by a decrease between 2014 and 2017, and a second high number of reported cases in 2019.  The number of congenital syphilis cases decreased again in 2020 and 2021. To achieve the 2030 target for the elimination of congenital syphilis, challenges in surveillance, diagnosis and treatment for pregnant women need to be overcome.

Altogether, these reports signal a critical juncture in the battle against STIs in Europe. Collaborative efforts among public health authorities, healthcare providers, and communities are essential to curb the spread of these infections and mitigate their impact on individuals and public health systems.