Are STDs common in Thailand? Sexually transmitted infections exist in Thailand just as they do in every country, and your personal risk depends far more on what you do than where you are. Condomless sex with new partners carries the same risks in Bangkok, Brighton or Berlin.
This guide gives you the official picture, the infections travellers most often pick up, and a simple plan for before, during and after your trip. It's written without scare stories, because the facts are enough.
What the official figures say
Many websites quote dramatic STD numbers without a source. We only use figures from official health bodies, and we name them.
According to UNAIDS' country focus on Thailand, around 480,000 people were living with HIV in Thailand in 2018. New infections that year were estimated at 6,400, a fall of 59% since 2010. UNAIDS also notes that Thailand provides HIV treatment free of charge through its universal health coverage.
Thailand's HIV response is widely recognised. In 2016, the World Health Organization validated Thailand as the first country in Asia to eliminate mother-to-child transmission of HIV and syphilis.
What about HIV in Thailand in 2026?
Estimates are updated every year, so always check the latest UNAIDS data for current numbers. The key point for travellers doesn't change: HIV is preventable with condoms, PrEP and, in an emergency, PEP.
People living with HIV who are on treatment with an undetectable viral load do not pass HIV on through sex (U=U). Many people living with HIV in Thailand, as elsewhere, are on effective treatment.
The STIs travellers pick up most
Travellers mostly catch the same infections they would at home. Many cause no symptoms, which is why testing matters even if you feel fine.
Common STIs for travellers: how they spread and how to test
| Infection | How it spreads | Often silent? | Test |
|---|---|---|---|
| Chlamydia | Vaginal, anal or oral sex | Yes, very often | Urine or swab |
| Gonorrhoea | Vaginal, anal or oral sex | Often, especially throat and rectum | Urine or swab |
| Syphilis | Skin contact with a sore during sex | Early sores can go unnoticed | Blood test |
| Herpes | Skin-to-skin contact | Often | Swab of a sore |
| HPV | Skin-to-skin contact | Usually | Cervical screening; no routine test for others |
| Hepatitis B | Sex, blood, shared needles | Often | Blood test |
| HIV | Condomless sex, shared needles | Often at first | Blood test |
For more detail on the most common two, read about chlamydia and gonorrhoea testing on Koh Samui. For a sore or rash, our guide to the syphilis test on Koh Samui covers signs and stages.
Symptoms that mean see a doctor now
Don't wait for a planned test date if you notice any of these:
- Discharge from the penis, vagina or anus
- Pain or burning when you pee
- A sore, ulcer or blister on or around the genitals or mouth
- A new rash, especially on the palms or soles
- Pain in the lower belly or testicles
- A flu-like illness a few weeks after sex
Don't self-treat with pharmacy antibiotics
Some travellers buy antibiotics over the counter and hope for the best. It's tempting, but the wrong medicine or dose can hide an infection without curing it and adds to antibiotic resistance, which is already a growing problem with gonorrhoea worldwide.
A proper test tells you exactly what you have, so you get the right treatment first time. The same goes for HIV medicines: our guide on buying PEP at a pharmacy in Thailand explains why a doctor's assessment matters.
Why holidays change the picture
It isn't Thailand that raises risk. It's the holiday mindset: new partners, more alcohol and less planning.
The US CDC's health advice for travellers to Thailand notes that people take more risks when intoxicated. It also recommends the hepatitis B vaccine for unvaccinated travellers younger than 60, and mentions mpox vaccination for travellers who may have sex with new partners. Talk to a travel clinic at home about which vaccines suit you.
Island parties can be great fun. If you're heading to one, our Full Moon Party sexual health guide explains what to do if something goes wrong.
Your prevention options
No single method covers everything. Most travellers combine two or three.
STI and HIV prevention options compared
| Option | Protects against | When to arrange | Good to know |
|---|---|---|---|
| Condoms | HIV, most STIs, pregnancy | Pack them; widely sold | Don't cover all skin-to-skin infections |
| HIV PrEP | HIV only | Ideally before travel | Needs a doctor and regular check-ups |
| Hepatitis B vaccine | Hepatitis B | Weeks before travel | Course of doses over time |
| HPV vaccine | Several HPV types | Ask your home doctor | Best before exposure |
| Regular testing | Finds infections early | During or after travel | Treats silent infections |
| HIV PEP | HIV only | Within 72 hours after exposure | Emergency, not routine |
If you're thinking about PrEP for your trip, our HIV PrEP service on Koh Samui can help you start before or during your stay.
Before, during and after your trip
A little planning takes most of the worry out of sexual health on holiday. Use this as a checklist.
Sexual health checklist for Thailand travellers
| Stage | What to do |
|---|---|
| Before you go | Get a check-up; ask about hepatitis B and HPV vaccines; consider PrEP; pack condoms |
| During your trip | Use condoms; keep alcohol in check; save a clinic's contact details in your phone |
| If something happens | Seek PEP within 72 hours for a possible HIV exposure; test if you get symptoms |
| After you get home | Test at the right times, even without symptoms; tell your doctor you travelled |
When to test after travel
Timing depends on the infection. Chlamydia and gonorrhoea can usually be found from about 2 weeks, while HIV and syphilis need a test at around 4–6 weeks and again at about 3 months.
Our full guide on when to get an STD test after unprotected sex sets out the timeline for every common infection, including when a negative result can be trusted.
If you need help on Koh Samui
If a condom broke or you had sex without protection, act fast. PEP must be started within 72 hours — the sooner the better. Our HIV PEP service on Koh Samui can assess you quickly.
For routine checks, our HIV and STI testing service covers the main infections. If you're moving around the country, read how to keep taking your 28-day PEP course while you travel.
Frequently asked questions
Are STDs more common in Thailand than at home?
STIs are found in every country. Your own risk depends mainly on condom use, number of partners and whether you test, rather than on the destination.
Should I get tested after a holiday fling?
Yes, if you had sex without a condom. Many STDs have no symptoms, so a test at the right time is the only way to know.
Can I get tested in Thailand before flying home?
Yes. Early tests can be done here, but some tests need repeating at about 3 months, so plan follow-up at home.
Which vaccines help protect against STIs?
Hepatitis B and HPV vaccines protect against those infections. Ask your doctor before you travel.
Does travel insurance cover STD tests or PEP?
It depends on your policy. Check the terms and keep receipts.
Travel with confidence
Knowing the facts, packing condoms and having a plan for emergencies are the best protection. If you're worried about a recent encounter, we're here to help without judgement.
Message a doctor privately on WhatsApp about STD risk or testing in Thailand.