How Condomless Sex is Fueling the STI Surge in Europe

In September 2023, the UK Health Security Agency urged students to use condoms and undergo regular STI testing to curb rising infections—a critical message that applies to everyone, not just students.

Data from the European Centre for Disease Prevention and Control reveals alarming trends: syphilis cases rose by 34% between 2021 and 2022, chlamydia by 16%, and gonorrhoea by 48%.

Rising Trends Across Europe and Ireland

Reflecting broader European trends, Ireland—where my research on sexual health is based—has seen a significant STI surge. Between 2019 and 2022, reported cases increased by:

• 20% for chlamydia,
• 45% for gonorrhoea,
• 14% for syphilis.

Young people under 30 are particularly affected. Women aged 20-24 show the highest STI notification rate at 3,088 per 100,000 population. Gonorrhoea cases in women aged 20-24 rose by 133% in 2023, while men aged 15-19 experienced a 55% increase.

Key Affected Populations

Gay, bisexual, and other men who have sex with men (MSM) account for a disproportionate share of infections. In Ireland, MSM represented 84% of gonorrhoea and 71% of syphilis cases in 2022.

For migrants, data are limited, but co-infection rates are concerning. Among new HIV diagnoses, 17% had bacterial STI co-infections, rising to 26% among MSM. Many new HIV cases were reported among migrants from Latin America (24%) and sub-Saharan Africa (20%).

The European MSM Internet Survey (EMIS) highlights additional challenges migrants face—including stigma, language barriers, limited sexual health knowledge, and financial constraints—that impede safer sexual practices. Refugees, particularly survivors of sexual violence, are at increased risk of STIs.

Decline in Condom Use: The Driving Factor

A sharp decline in condom use remains central to the rise in STIs, especially among young people and MSM.

What’s behind this decline?

The answer is complex. Sexual health is shaped by an interplay of individual, social, and structural factors—a perspective known as the socio-ecological approach. Shifts in culture, technology, and society have reshaped sexual behaviors, yet remain underexplored.

• Smartphones and Dating Apps: Online dating apps have made meeting partners easier but are linked to higher rates of gonorrhoea and chlamydia. Similarly, increased pornography consumption correlates with more instances of condomless sex.
• PrEP Usage: While pre-exposure prophylaxis (PrEP) has been pivotal in reducing HIV transmission among MSM, its use is also associated with higher STI rates.
• Drug Use: MSM diagnosed with STIs in Ireland are 53% more likely to engage in recreational drug use, further influencing risky behaviors.
• Housing Instability: Homelessness, which is rising across Europe, exacerbates unsafe sexual practices. Youth homelessness in Ireland alone increased by 57% between 2017 and 2022.
• Migration: Inward migration to Ireland rose by 31% in 2023. Barriers to healthcare access, such as affordability, stigma, and language, further limit migrants’ ability to protect their sexual health.

Addressing the STI Crisis: A Holistic Approach

To reverse these trends, we must address the root causes of rising STIs:

1. Improve Access to Testing and Services: Free testing initiatives like SH:24 have enhanced access in Ireland. Peer-led community testing, effective in Dublin, must expand beyond urban centers.
2. Tackle Socioeconomic Determinants: Investment in education, housing, and overall living conditions—particularly for marginalized groups—is vital.
3. Promote Education and Awareness: Comprehensive, culturally sensitive sexual health education is key to empowering individuals to make safer choices.
4. Address Structural Barriers: Policies must combat stigma and discrimination while ensuring equal access to services for all, including migrants and LGBTQ+ communities.

A Shared Responsibility

Everyone has the right to a safe, healthy, and fulfilling sex life. To stem the rise of STIs, governments, healthcare providers, and communities must collaborate to create supportive environments that prioritize prevention, testing, and education. By promoting dignity, equality, and access to essential services, we can protect sexual health and reverse the tide of rising infections in Europe.