Two sexually transmitted diseases have reached their highest levels in over a decade, with gonorrhoea and syphilis diagnoses surging across Europe and remaining alarmingly high in the UK. The European Centre for Disease Prevention and Control (ECDC) reported that in 2024, gonorrhoea cases across Europe hit 106,331 — a 303% increase since 2015 — while syphilis more than doubled over the same period to 45,557. Spain recorded the highest numbers, with 37,169 gonorrhoea cases and 11,556 syphilis cases last year. In England, the UK Health Security Agency (UKHSA) documented 71,802 gonorrhoea diagnoses and 9,535 infectious syphilis cases in 2024. Although gonorrhoea diagnoses fell by 15.9% from the previous year, levels remain stubbornly high. Syphilis, meanwhile, rose by 1.7% from 2023, and when late-stage infections and complications are included, the total reached 13,030 — a 4.6% increase.
Despite these worrying trends, chlamydia remains the most commonly diagnosed STI in the UK, with 168,889 cases recorded in England in 2024. Young people aged 15 to 24, gay and bisexual men, and some minority ethnic groups continue to bear the highest burden of infection. London has the highest number of new STI diagnoses in England, while the North East has the lowest.
Gonorrhoea: symptoms, treatment and the threat of resistance
Gonorrhoea, the second most common bacterial STI in the UK after chlamydia and sometimes known colloquially as ‘the clap’, spreads through unprotected vaginal, oral or anal sex, as well as through sharing sex toys that have not been washed or covered with a fresh condom. The infection can affect the cervix, urethra, rectum, throat and eyes, and can be passed from a pregnant person to their baby, potentially causing blindness if left untreated.
Symptoms differ between men and women, but many people experience none at all. According to the NHS, women may notice a yellow or greenish vaginal discharge, a burning pain when urinating, lower abdominal pain, or — very rarely — bleeding between periods. Men often report a burning sensation when passing urine, a discharge from the penis, or sore testicles. Infection in other parts of the body can cause anal pain, itching and discharge, a sore throat, or red, painful eyes with discharge. Around one in ten infected men and almost half of infected women have no symptoms, making regular testing essential for anyone who is sexually active.
Dr Hana Patel, a GP and consultant for Superdrug Online Doctor, advises waiting two weeks after potential exposure before testing for gonorrhoea. “Women may experience more subtle symptoms than men, which can make the infection easy to overlook,” she said. Testing is done via a swab or urine sample, and treatment can begin before results are confirmed. The standard therapy is a single injection of ceftriaxone, sometimes combined with oral antibiotics.
If left untreated, gonorrhoea can lead to pelvic inflammatory disease, ectopic pregnancy, infertility and, in rare cases, life-threatening sepsis. Repeated infections increase the risk of complications. A further concern is the emergence of antibiotic-resistant strains. The ECDC has noted a rise in extensively drug-resistant (XDR) gonorrhoea, with ceftriaxone — the frontline treatment — becoming less effective against certain strains, particularly those linked to travel in the Asia-Pacific region.
Syphilis: a stealthy infection with serious long-term risks
Syphilis is less common than gonorrhoea but equally dangerous if missed. Symptoms can be mild, making the infection easy to overlook. According to UKHSA and NHS guidance, the first sign is often small, painless sores — known as chancres — on the penis, vagina, bottom or mouth. White or grey warty growths may also appear. Later, a rash can develop on the palms of the hands or soles of the feet, along with swollen glands, flu-like symptoms and patchy hair loss.
Dr Patel explained that testing for syphilis should wait four to 12 weeks after exposure because antibodies take time to reach detectable levels. The infection is diagnosed through a blood test or a swab of a sore. Treatment involves antibiotics, typically an injection of penicillin or a course of tablets.
Untreated syphilis can cause devastating long-term damage to the heart, brain and nervous system, leading to stroke, blindness, dementia and even death. A particularly alarming trend highlighted by the ECDC is the near doubling of congenital syphilis cases — passed from mother to baby — across Europe between 2023 and 2024.
Condom use more important than ever
With STIs rising and antibiotic-resistant strains of gonorrhoea circulating, health officials stress that condoms remain the main defence against infection. Dr Katy Sinka, consultant epidemiologist and head of the STI section at UKHSA, said: “Condoms aren’t just about preventing unwanted pregnancy; they are the main defence against STIs. If you have had condomless sex with a new or casual partner, it is even more important to get tested to detect any potential infections early and prevent passing them on to others.”
Yet data from Durex suggests that condom use among UK adults is far from universal. In 2023, only 15% of people purchased condoms, and a staggering 41% skipped any form of contraception at all. Free condoms are available at local sexual health clinics, and for those under 25, the NHS offers them online. Free, confidential testing for STIs is also widely available through sexual health clinics, some GP surgeries and online services.