STI Prevention: Myths vs Facts

How STIs spread

"The most effective STI prevention strategy combines barrier methods with regular screening. Most of the patients I see with complications had infections that were completely treatable — they just didn't know they had them."

— Dr Mohammad Bakhtiar, Clinical Lead, Sexual Health Clinic London

Sexually transmitted infections are caused by bacteria, viruses, or parasites passed between people during vaginal, anal, or oral sex, and in some cases through skin-to-skin genital contact; most STIs produce no symptoms at all in the early stages, which is why regular testing is the single most effective prevention strategy.

STIs spread through three main routes:

Bodily fluids. HIV, gonorrhoea, chlamydia, and hepatitis B are transmitted through semen, vaginal fluids, and blood. Condoms are highly effective against these infections because they prevent fluid exchange.

Skin-to-skin contact. Herpes (HSV), syphilis, and HPV can spread through direct contact with infected skin, sores, or warts, including areas not covered by a condom. This is why condoms reduce rather than eliminate risk for these infections.

Shared items. Some infections, particularly trichomoniasis, can be transmitted through shared sex toys. Hepatitis B can survive outside the body for up to seven days on surfaces.

Understanding the route matters because it determines which prevention methods work best for which infections.

Prevention strategies that actually work

No single method provides 100% protection against all STIs. Effective prevention combines multiple approaches.

Condoms

Condoms remain the most accessible and broadly effective barrier method. When used consistently and correctly, they provide high levels of protection against STIs transmitted through bodily fluids: HIV, gonorrhoea, chlamydia, and trichomoniasis.

For infections spread by skin-to-skin contact (herpes, syphilis, HPV), condoms reduce risk but cannot eliminate it entirely, because they do not cover all potentially infected skin. A review of prospective studies published in the Bulletin of the World Health Organization found condom use associated with statistically significant protection against chlamydia, gonorrhoea, HSV-2, and syphilis in both men and women.

Key points:

Latex and polyurethane condoms both provide effective STI protection. Lambskin condoms do not block viral transmission and should not be used for STI prevention. Use water-based or silicone-based lubricant with latex condoms; oil-based lubricants degrade latex. A new condom is needed for each act of vaginal, anal, or oral sex and when switching between acts.

Vaccination

Two vaccines are directly relevant to STI prevention in the UK:

HPV vaccination. The NHS offers HPV vaccination to all children aged 12-13. The vaccine protects against HPV types 16 and 18 (responsible for the majority of HPV-related cancers) and types 6 and 11 (responsible for most genital warts). UKHSA 2024 data shows genital warts diagnoses in 15-17 year olds dropped to just 78 cases, down from several thousand before the vaccination programme began. If you missed the school programme, we offer HPV testing and can advise on catch-up vaccination.

Hepatitis B vaccination. Effective and widely available. Recommended for anyone at ongoing risk, including people with multiple sexual partners and men who have sex with men. We test for hepatitis B as part of our Gold and Platinum screening packages.

Gonorrhoea vaccination. From August 2025, the NHS began offering meningococcal B vaccination to eligible groups to reduce gonorrhoea risk. Early evidence from other countries suggests approximately 30% protection against gonorrhoea. This is a new development and not a substitute for condom use or testing.

Regular testing

This is the most underused prevention strategy. Most STIs produce no symptoms, particularly in women. Chlamydia, gonorrhoea, syphilis, HIV, and hepatitis B can all be present for months or years without any outward sign. You cannot tell whether you or a partner is infected by looking, feeling, or asking.

BASHH recommends:

Testing at least annually if you are sexually active with new or casual partners. Testing after every new sexual partner, ideally before first sexual contact with the next partner. Testing after any unprotected sex with a partner of unknown status. Routine screening every 3 months for men who have sex with men with multiple partners.

We offer walk-in testing at 117a Harley Street six days a week, with results from 4 hours for our FAST Screen (£350) or 24 hours for standard packages. No GP referral needed.

Communication with partners

Discussing sexual health with a new partner before sex is straightforward and effective. It does not need to be a formal conversation. Knowing whether a partner has been recently tested, or agreeing to get tested together before starting a sexual relationship, substantially reduces risk.

Reducing number of concurrent partners

Higher numbers of sexual partners correlate with higher STI risk. This is a statistical observation, not a moral judgement. If you have multiple partners, consistent condom use and more frequent testing become proportionally more important.

STI myths vs facts

Myth: "I would know if I had an STI"

This is the single most dangerous misconception. The majority of STIs are asymptomatic in their early stages.

Chlamydia produces no symptoms in approximately 70% of women and 50% of men. Gonorrhoea is asymptomatic in up to 50% of women and 10% of men with urethral infection; pharyngeal and rectal infections are usually silent regardless of gender. HIV can remain symptom-free for a decade or more after the acute phase. Syphilis chancres are painless and often hidden internally in women. Herpes can shed virus on approximately 10% of days without any visible sores.

The absence of symptoms does not mean the absence of infection. It means the absence of information. Only testing provides that.

Myth: "You cannot get STIs from oral sex"

You can. Oral sex carries lower risk than vaginal or anal sex for most infections, but it is not risk-free.

Gonorrhoea commonly infects the throat through oral sex, and pharyngeal gonorrhoea is usually asymptomatic. Syphilis can be transmitted through oral contact with a chancre. Herpes (both HSV-1 and HSV-2) is readily transmitted between mouth and genitals. Chlamydia can infect the throat, though this is less common. HPV can be transmitted orally and is linked to oropharyngeal cancers.

If you have unprotected oral sex with new partners, request throat swab testing in addition to genital testing. Our Silver, Gold, and Platinum screening packages include multi-site testing.

Myth: "Only young people get STIs"

STI diagnoses among people aged 50-70 have increased substantially over the past decade. UKHSA data consistently shows rising rates in older age groups, driven by factors including post-divorce dating, lower perceived risk leading to less condom use, and reduced likelihood of seeking testing.

Age does not protect you. Sexual activity at any age carries STI risk if condoms are not used consistently and testing is not routine.

Myth: "I have only had one partner, so I do not need testing"

You need only one sexual contact to acquire an STI. Your risk depends not just on your own behaviour but on your partner's history, which you may not fully know. A single episode of unprotected sex with an infected partner is sufficient for transmission of chlamydia, gonorrhoea, syphilis, HIV, herpes, or HPV.

Additionally, some STIs can be acquired through non-penetrative contact. HSV-1 (the cold sore virus) is the most common cause of new genital herpes diagnoses in the UK, often transmitted through oral sex.

Myth: "We are both monogamous, so we do not need to test"

If both partners tested negative for all STIs before the relationship began, and neither has had other sexual contact since, then retesting is not clinically indicated. However, many couples assume mutual negative status without either partner actually having been tested. Previous partners may have transmitted infections that are currently dormant.

The practical advice: get tested together at the start of a new relationship. It removes the guesswork and is one of the most responsible things you can do for each other.

Myth: "Condoms provide complete protection"

Condoms substantially reduce STI risk but do not eliminate it entirely. They are most effective against infections transmitted through bodily fluids (HIV, chlamydia, gonorrhoea). For infections spread through skin-to-skin contact (herpes, syphilis, HPV), condoms reduce risk only for areas they cover.

This is not an argument against condom use. It is an argument for combining condom use with regular testing. Condoms lower your probability of infection per encounter; testing catches anything that gets through.

Myth: "STI testing is painful or embarrassing"

Most STI tests require a urine sample and a blood draw. That is it. If you have symptoms, a swab may be taken from the affected area, which takes seconds and causes minimal discomfort.

At our clinic, you can walk in without an appointment, register under a pseudonym, and pay by cash. The consultation is private, the process is quick, and nobody in the waiting room knows why you are there. We see thousands of patients a year for sexual health screening. There is nothing unusual about looking after your health.

Myth: "All STIs are curable"

Bacterial STIs (chlamydia, gonorrhoea, syphilis) are curable with antibiotics, though antibiotic-resistant gonorrhoea is a growing concern. UKHSA reported 13 ceftriaxone-resistant cases in 2024 and 14 in just the first five months of 2025, six of which were extensively drug-resistant.

Viral STIs are not curable. HIV is managed with lifelong antiretroviral therapy (highly effective, near-normal life expectancy). Herpes recurs periodically and is managed with antivirals. HPV often clears naturally but can persist and cause complications. Hepatitis B can become chronic.

Early diagnosis matters for all STIs, curable or not. It prevents complications, stops onward transmission, and in the case of syphilis and HIV, the difference between early and late treatment is the difference between straightforward management and serious harm.

Myth: "You cannot get the same STI twice"

You can. There is no lasting immunity to chlamydia, gonorrhoea, syphilis, or trichomoniasis after treatment. You can be reinfected immediately upon re-exposure. This is why partner notification and treatment matter: if your partner is not treated simultaneously, reinfection is likely.

For viral STIs, the picture is different. Once you have herpes or HIV, the infection is lifelong (though manageable). You cannot be "reinfected" with the same strain, but you can acquire a different type (for example, acquiring HSV-2 when you already have HSV-1).

Myth: "Syphilis is a disease of the past"

Syphilis diagnoses in England reached their highest level since the 1940s in 2023, with 9,513 infectious syphilis diagnoses. In 2024, early-stage syphilis rose a further 2% to 9,535 cases, and total syphilis diagnoses (including late-stage) reached 13,030. Recent increases have been relatively higher among heterosexual men and women than among gay and bisexual men, meaning the infection is spreading into populations that may not consider themselves at risk.

Syphilis is entirely curable with a single penicillin injection when caught early. Our clinic provides both testing and in-house treatment, including benzathine penicillin injection on-site.

Myth: "Home test kits are just as good as clinic testing"

Home kits serve a purpose, particularly for people who cannot easily access a clinic. But they have limitations. They test for fewer infections (typically chlamydia, gonorrhoea, HIV, and syphilis). They do not include pharyngeal or rectal swabs. They cannot perform a physical examination. They do not include a doctor consultation. And inconclusive or borderline results, which are more common with self-collected samples, require a clinic visit anyway.

If your home test was unclear, if you have symptoms, or if you want comprehensive testing including examination and clinical advice, a face-to-face consultation provides what a postal kit cannot.

What to test for and how often

Your situation	Recommended approach	Our packages
New sexual partner	Test before or soon after first sexual contact	Bronze Screen: £250 (HIV, syphilis, chlamydia, gonorrhoea)
Multiple partners, heterosexual	Test at least annually, or after each new partner	Silver Screen: £325M / £375F (adds herpes, mycoplasma, ureaplasma, trichomoniasis)
MSM, multiple partners	Test every 3 months (BASHH recommendation)	MSM packages with multi-site testing
Post-condom failure or known exposure	Test at appropriate window periods	FAST Screen: £350 (results in 6 hours)
Starting a new monogamous relationship	Test together at the beginning	Gold Screen: £475M / £490F (comprehensive including hepatitis)
Symptoms present	Test immediately	Walk in to 117a Harley Street, no appointment needed

All packages include a consultation with a doctor (£150 value included), UKAS-accredited laboratory testing, and results within stated timeframes.

Why choose our clinic for STI testing

We are a private sexual health clinic at 117a Harley Street, established in 1984, with over 70,000 patients seen. For STI testing specifically:

Same-day results available through our FAST Screen service (6-hour turnaround for HIV, syphilis, chlamydia, and gonorrhoea). Walk-in appointments six days a week; no GP referral required. Pseudonymous registration and cash payment accepted for complete privacy. UKAS-accredited laboratory partners (the same accreditation standard used by NHS laboratories). Doctor consultation, physical examination if needed, and prescriptions included in all packages. In-house syphilis treatment with benzathine penicillin injection; most private clinics test only and refer elsewhere for treatment.

We do not offer PrEP or PEP. If you need post-exposure prophylaxis for HIV, contact your nearest sexual health clinic or A&E within 72 hours. Do not delay.

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References:

1. UKHSA (2025). Sexually transmitted infections: annual data tables, England 2024.
2. BASHH (2024). UK National Guidelines for the Management of STIs.
3. Holmes, K.K. et al. (2004). Effectiveness of condoms in preventing sexually transmitted infections. Bulletin of the WHO, 82(6), 454-461.
4. NICE CKS (2024). Sexually transmitted infections - general approach.
5. BHIVA/BASHH/BIA (2020). UK National Guidelines for HIV Testing.