Sex and travel: sexually transmitted infections

Advice about reducing risk of sexually transmitted infections (STIs) during travel

Key messages

Sexually transmitted infections (STIs) are viruses, bacteria and parasitic infections that are spread during sex and intimate contact.
Many STIs can be treated, but some can cause complications or serious illness.
STIs are a risk worldwide and anyone who is sexually active is at risk.
Some world regions have higher rates of STIs (including blood-borne viruses like hepatitis B and HIV) compared to the UK.
It is estimated that up to 20 percent of travellers will have a sexual encounter abroad, with sexual risk-taking abroad often linked to alcohol.
Travellers should be aware of risks linked to casual sex abroad and carry and use reliable condoms for protection.
In the UK, anyone worried they may have an STI can arrange free, confidential testing at an NHS sexual health clinic.
Remember – some STIs do not have any symptoms.

Overview

Travel often involves new experiences and being abroad can make travellers less inhibited. This may lead to riskier behaviour, including having unprotected sex with new or multiple partners. Alcohol and other drugs help lower inhibitions, while dating apps make it easy for travellers to meet potential partners, increasing their chance of risky encounters [1].

Sexually transmitted infections (STIs) are viruses, bacteria and parasitic infections usually spread during sex or intimate contact. The World Health Organization (WHO) estimates that more than one million people worldwide catch a curable STI every day [2].

According to WHO, human immunodeficiency virus (HIV), viral hepatitis and STIs collectively cause 2.3 million deaths and 1.2 million cases of cancer each year [3]. Approximately 374 million people catch one of these four STIs every year: chlamydia, gonorrhoea, syphilis and trichomoniasis [2]. STIs are more common in low-income countries [1, 2].

While many STIs can be treated, some can still lead to serious health problems, including pregnancy complications and infertility. Infection with some strains of human papillomavirus (HPV) is linked to cancers of the cervix, vulva, vagina, mouth/throat, penis and anus [2]. If left untreated, some STIs can be life-threatening [3].

Emerging outbreaks of newer infections that can be acquired during sex, include Ebola disease, mpox, Neisseria meningitidis, Shigella (a bacterium infection that causes diarrhoea, stomach cramps and flu like illness) and Zika virus infection. The re-emergence of neglected STIs, such as lymphogranuloma venereum, are also being reported globally [2].

Certain STIs are also becoming harder to cure, as they are becoming resistant to the drugs normally used to treat them. For example, an increasing number of multi-drug resistant cases of gonorrhoea [4, 5] and Shigella [6-8] have been linked to international travel.

Risk areas

STIs occur worldwide – anyone having sex is at risk. However, rates of some STIs, including blood-borne viruses such as hepatitis B and HIV, are significantly higher in low- and middle-income countries [1]. These countries may have significant challenges in providing health services to diagnose and treat STIs [2].

Risk for travellers

STI risk depends on behaviour (like unprotected sex) and also by how common STIs are at the traveller's destination. Staying safe means being aware and following safer sex guidelines.

Sexual risk taking is influenced by various factors, including changes in social environment and alcohol and/or other drug use. Research shows that approximately 20–34% of male travellers will have casual sex abroad and that about half of all travellers having casual sex abroad will not use condoms. Long trips, travelling alone or with friends, younger age and being single are other factors linked to casual sex during international travel [1].

Travellers at increased risk of STIs

Young travellers can be more likely to have sex abroad. Anonymity of travel and independence from social networks at home are recognised as contributing factors to increased sexual activity abroad. The perception that restrictions, obligations and rules are left behind, means that a "what happens in Vegas stays in Vegas" culture is often embraced by young adults abroad [9].

Gay, bisexual and other men who have sex with men (GBMSM) are at higher risk of new sexual partnerships and having unprotected sex abroad [1, 7, 8, 10, 11].

People who travel frequently or spend long periods abroad – these include the armed forces, aid workers, airline crew, backpackers, business travellers, cruise staff, diplomats, expatriates, international students, long distance lorry drivers, migrant workers, seafarers, teachers and people visiting friends and family [1].

Sex tourists – some people, both men and women, travel specifically for sex. This is sometimes known as "sex tourism". Having condomless sex with sex workers is associated with an increased risk for STIs, as infection rates, including HIV, are higher in sex workers and local people who have sex with tourists [1]. Multidrug-resistant gonorrhoea infections have been linked to encounters with sex workers [1, 5].

Transmission

Depending on the infection, STIs can be spread during unprotected sex – including vaginal, anal and oral sex [2]. Some infections can be spread by intimate skin-to-skin contact.

Certain STIs, including HIV, hepatitis B, hepatitis C and, more rarely syphilis, can also be transmitted via unsafe blood transfusion/blood products or contaminated needles/syringes and medical equipment [2].

Infections can also spread from mother to baby in pregnancy (hepatitis B, hepatitis C, HIV, syphilis and Zika virus), during childbirth (chlamydia, gonorrhoea, hepatitis B, hepatitis C, herpes, HIV and syphilis) or during breastfeeding (HIV) [1, 2].

As well as sex, activities that can put travellers at risk include recreational drug use, any procedure that could involve contaminated needles, syringes or medical equipment; body piercing, cosmetic and dental procedures (including surgery), medical treatment and tattoos.

Hepatitis A can also be spread during sex or by blood transfusion/blood products.

Signs and symptoms

As STIs are caused by a wide variety of different bacteria, viruses and parasites, they can cause a range of symptoms, depending on the infection [2].

See Disease section below for links to specific STI information and remember some STIs do not cause any symptoms at all.

Disease information

Some more commonly known STIs include:

Chancroid

Chlamydia

Donovanosis

Genital herpes simplex 1 and 2

Genital warts and human papillomavirus (HPV)

Human Immunodeficiency Virus (HIV)

Lymphogranuloma venerum

Preventing STIs

Research highlights that although travellers usually have adequate knowledge of STIs, including HIV, they often think they are not at any personal risk [12].

Travellers should be advised about their risk of getting STIs abroad.

Recommended elements of a pre-travel clinical consultation include the following:

STI and HIV prevention guidance, such as consistent use of condoms
STI and HIV pre and post exposure prophylaxis discussion
options for contraception (including emergency contraception) if appropriate
vaccine recommendations [1]

A review article on the effect of pre-travel STI prevention advice recommends highlighting that casual sex abroad is often unplanned and suggests giving travellers written information on both prevention and post-exposure management to take away [12].

Ideally avoiding (abstinence) sex with new or known to be infected partners is the best way to prevent STIs, but this can be challenging.

Condoms

Condom effectiveness differs by STI. Correct, consistent use of condoms is highly effective at preventing STIs that spread via sexual fluids, such as gonorrhoea, chlamydia and HIV. However, condoms only offer limited protection against STIs that spread by skin-to-skin contact, for example syphilis, genital herpes and HPV [10].

In the UK, condoms should carry a BSI or CE kite-mark and travellers should carry a good supply of these condoms when going abroad. If buying condoms overseas, travellers should follow the advice below:

Check condoms carry a recognised mark of quality e.g. European kite-mark, International Standards Organisation (ISO) mark or approval by the US Food and Drug Administration (FDA).
Male condoms are available worldwide, with female condoms available in some countries.
Fake (counterfeit) condoms may be for sale abroad. These may also carry the quality marks. Counterfeit condoms may fail to protect against STIs and unwanted pregnancy. Male condoms manufactured in South and Southeast Asia are made slightly narrower than those available in the UK.
Condoms should not be used after they expire (check packet for expiry date).

Pre-exposure prophylaxis (PrEP)

HIV pre-exposure prophylaxis (PrEP) is a single tablet of combined HIV drugs taken, either daily, or on demand before and after sex, to prevent HIV infection. This medicine stops the HIV virus from getting into the body and replicating. When taken correctly, daily PrEP is 99% effective. In the UK, HIV PrEP has been routinely available through sexual health clinics since 2020 [13].

A two-monthly HIV PrEP injection, offering an alternative for people unable to take tablets is now also available in parts of the UK for some individuals [13, 14].

Post-exposure prophylaxis (PEP)

HIV PEP
HIV post-exposure prophylaxis (PEP) is a combination of HIV drugs that can be taken after unprotected sex to try to stop HIV infection. Like HIV PrEP, it is available from sexual health clinics in the UK. It can be used within 72 hours (three days) after a potential exposure. However, HIV PEP is not a 'morning after pill' for HIV and is not guaranteed to work. It is meant as an emergency measure to be used as a last resort, such as if a condom fails during sex [15].

Antibiotic (doxycycline) PEP
An antibiotic, doxycycline is available in the UK from sexual health clinics as a way of helping prevent bacterial STIs after sex. Doxycycline post-exposure prophylaxis (doxyPEP) is known to be effective in preventing syphilis, chlamydia, and to a lesser extent gonorrhoea [16, 17]. Users take 200 mg of doxycycline up to 72 hours after condomless sex [17].

Hepatitis A and B PEP
An injection of human normal immunoglobulin (HNIG) may provide short term protection (immunity) in the first seven days after a hepatitis A exposure. In the UK, after a careful assessment, HNIG may be offered to an unvaccinated individual who had sexual contact with someone with infectious hepatitis A up to 14 days after exposure. This is in addition to hepatitis A vaccine [18].

Another injection, human hepatitis B specific immunoglobulin (HBIG) may be offered, after a careful assessment, to unvaccinated individuals who had unprotected sexual contact with someone infected with hepatitis B in the past seven days. This is in addition to hepatitis B vaccination [19].

In the UK, PrEP and PEP are generally available from sexual health clinics.

Vaccine information

There are some vaccines available in the UK that help prevent STIs.

Vaccine-preventable STIs

As hepatitis A and B vaccines provide protection against sexual transmission of these viruses, in the UK they are available free of charge from NHS sexual health clinics.

HPV are a group of viruses that can cause infections that may develop into a type of cancer or genital warts. It's very common, most people will get some form of HPV at some point in their lives. These viruses can be passed on through any kind of sexual contact with someone with HPV and sometimes also by non-sexual contact [20].

In the UK, a vaccine to protect against the HPV strains linked to genital warts and abnormal cell changes that can develop into cancer, is currently offered to young people aged 12-13 years and is available until their 25th birthday. This vaccine is also offered (via UK sexual health clinics) to people at higher risk from HPV. This includes GBMSM up to 45 years, any transgender people felt to have the same risk as GBMSM, sex workers and people with HIV [21-23].

In the UK, anyone who is considered at higher risk of gonorrhoea infection, including some GBMSM, is offered the meningococcal group B vaccine to help protect them against gonorrhoea. This vaccine also helps prevent meningitis and septicaemia caused by meningococcal B bacteria [24].

Contraception and emergency contraception abroad

Contraception may be completely unavailable or hard to access in some countries. This can be due to cultural and/or religious factors, lack of health services, provider bias and gender-based barriers [25].

The emergency contraceptive pill – also called the 'morning after pill', is usually effective if taken within 72 hours of unprotected sex and may be available in some countries.

Getting an intrauterine contraceptive device – also known as a coil or an IUD, fitted within five days of unprotected sex may prevent pregnancy. However, this is not available in many countries and is not recommend anywhere with a high risk of blood-borne viruses.

Diagnosis and treatment

Eight infections account for the most frequently reported STIs worldwide. Four are currently curable: syphilis, gonorrhoea, chlamydia and trichomoniasis. The other four are viral infections: hepatitis B, herpes simplex virus, HIV and HPV [2].

In the UK, free, confidential STI testing (and treatment if needed) is available from sexual health clinics to everyone, whatever their age, gender, ethnicity or sexuality [26].

See UK Health Security Agency – Getting tested for an STI: Your guide to how it works for more information, including how to access help and advice. Many STIs can be treated; early diagnosis and treatment will help prevent complications.

Some pharmacies and GP surgeries may also offer STI testing.

If you had unprotected sex or have been at risk of an STI abroad, get medical advice and testing as soon as possible, even if you do not have any symptoms. Avoid sex and intimate contact until all your STI screening tests have been done and either you have completed a full course of treatment or your test results are back and show you do not have any STIs.

UK treatment and management guidelines for STIs are available from British Association for Sexual Health and HIV.

Resources

References

First published : 09 December 2025 Last updated : 09 December 2025

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