Can You Get the Same STI Twice? Reinfection & Recurrence Explained

Can You Get the Same STI Twice? Reinfection & Recurrence Explained

One of the most common questions in sexual health is whether you can get the same STI twice. It is a reasonable assumption that once you have had an infection and been treated, your body would develop immunity — similar to how certain childhood illnesses work. However, the reality with sexually transmitted infections is more nuanced. Many STIs do not produce lasting immunity, which means reinfection is entirely possible. Some infections, meanwhile, are never fully cleared and can reactivate within the body at a later date. Understanding the difference between reinfection and recurrence is important for protecting your health and making informed decisions about testing and treatment. In this article, we explain which STIs can be caught again, why reinfection happens, and how to reduce your risk.

What Is STI Reinfection?

Reinfection means that you were previously treated for an STI, the treatment was successful and the infection was cleared, and you subsequently acquired the same infection again — typically from a new sexual exposure or from an untreated partner.

It is important to distinguish reinfection from treatment failure. Treatment failure occurs when the original course of treatment does not fully clear the infection — for example, due to antibiotic resistance or not completing the prescribed course. Reinfection, by contrast, occurs after the original infection has been successfully resolved.

In practice, the distinction matters because the clinical approach is different. Treatment failure may require an alternative antibiotic or a different treatment regimen, whereas reinfection is treated in the same way as a first infection and also prompts a conversation about partner treatment and prevention.

Which STIs Can You Get More Than Once?

Several of the most common STIs do not provide lasting immunity after infection and treatment. This means that you can get the same STI twice — or indeed multiple times — if you are exposed again.

Chlamydia

Chlamydia is one of the STIs most commonly associated with reinfection. Having had chlamydia and completing treatment does not provide any meaningful protective immunity. If you are subsequently exposed to Chlamydia trachomatis — whether from a new partner or an untreated existing partner — you can become infected again. Repeat chlamydia infection is common, particularly among younger adults, and this is one of the reasons why follow-up testing may be recommended after treatment.

Gonorrhoea

Like chlamydia, gonorrhoea does not produce lasting immunity. You can get gonorrhoea again after successful antibiotic treatment if you are re-exposed. It is worth noting that antibiotic resistance in gonorrhoea is a growing concern — though this is a separate issue from reinfection. Antibiotic-resistant strains require different treatment approaches but do not make reinfection itself more or less likely. For more on this topic, read our guide on super gonorrhoea explained.

Syphilis

Syphilis can also be acquired again after treatment. Successful treatment clears the active infection, but it does not protect against future exposure. Reinfection with syphilis is possible at any stage, and repeat infections require the same treatment and monitoring as initial cases.

Mycoplasma Genitalium

Mycoplasma genitalium is a bacterial infection that can be treated with antibiotics. As with other bacterial STIs, successful treatment does not confer immunity, and reinfection is possible with subsequent exposure. Treatment can sometimes be more complex due to emerging antibiotic resistance patterns, making appropriate testing and guided treatment important.

STIs That Can "Come Back" Without New Exposure

Not all STIs that appear to return are reinfections. Some infections remain in the body after the initial episode and can reactivate at a later date — even without any new sexual exposure. This is known as recurrence, and it is fundamentally different from reinfection.

Herpes (HSV)

Herpes simplex virus — both HSV-1 and HSV-2 — is a lifelong infection. After the initial outbreak, the virus retreats into nerve cells where it remains dormant. It can reactivate periodically, causing recurrent outbreaks of blisters or sores. These recurrences are not new infections; they are the same virus reactivating from within the body.

The frequency and severity of herpes outbreaks varies significantly between individuals. Some people experience frequent recurrences, while others may have very few or none at all. Antiviral medication can help manage outbreaks and reduce their frequency. For practical guidance, see our article on how to treat herpes sores.

It is worth noting that while herpes recurrences do not represent new infection, it is possible to acquire a different strain of herpes (for example, acquiring HSV-1 genitally if you already have HSV-2) through a new exposure.

HPV (Human Papillomavirus)

HPV is another virus that can persist in the body. In many cases, the immune system clears HPV naturally over time — often within one to two years. However, in some individuals, the virus may persist at low levels and can reactivate. It is also possible to be reinfected with a different HPV strain through new sexual contact.

The key distinction with HPV is that a recurrence of symptoms — such as genital warts — may reflect viral persistence and reactivation rather than a new infection. Your GP or sexual health clinician can help determine the most appropriate course of action if warts recur.

Why Does Reinfection Happen?

Reinfection with an STI is more common than many people realise, and there are several straightforward reasons why it occurs:

• Partner not treated — If your sexual partner was not tested and treated at the same time as you, they may still carry the infection and pass it back to you. This is one of the most common causes of apparent reinfection, particularly for chlamydia and gonorrhoea.
• New partner exposure — Acquiring a new sexual partner who carries an STI can result in infection regardless of your previous treatment history.
• Unprotected sexual contact — Sexual contact without barrier protection increases the risk of STI transmission, including reinfection with an STI you have previously had.
• Not waiting the recommended period after treatment — Most STI treatments require a period of abstinence or condom use before resuming sexual activity. Having sex too soon after treatment — before the infection is fully cleared — can result in transmission to a partner and subsequent re-exposure.

Reinfection is not a reflection of personal failure or poor judgement. It is a common and manageable aspect of sexual health that can be addressed through testing, treatment, and practical prevention measures.

How Soon After Treatment Can You Get Reinfected?

Once your treatment has cleared the original infection, reinfection can occur as soon as you are exposed to the same pathogen again. Antibiotics treat the current infection — they do not provide any ongoing protection against future exposure.

This is an important distinction: completing a course of antibiotics for chlamydia, for example, means the chlamydia is cleared from your body, but you have no immunity. If you have sexual contact with an infected partner the day after completing treatment, you can acquire the infection again.

For this reason, clinicians typically advise a waiting period after treatment before resuming sexual activity. The specific advice varies by infection and treatment type, but common guidance includes:

• Chlamydia — avoid sexual contact for at least 7 days after completing treatment (or until both you and your partner have finished treatment)
• Gonorrhoea — avoid sexual contact until both partners have been treated and any follow-up testing confirms clearance
• Syphilis — your GP or sexual health clinician will advise based on the stage of infection and treatment given

Following these recommendations significantly reduces the risk of reinfection and onward transmission.

How to Reduce the Risk of Getting the Same STI Again

While reinfection cannot always be prevented, there are practical steps that significantly reduce the risk:

• Ensure your partner is treated — If you test positive for an STI, it is important that your sexual partner or partners are also tested and treated. Partner notification services can help with this process if direct conversation feels difficult.
• Complete the recommended waiting period — Follow clinician advice regarding when it is safe to resume sexual activity after treatment. This protects both you and your partner.
• Use condoms consistently — Condom use substantially reduces the risk of STI transmission, though it is not a guarantee — particularly for infections transmitted through skin-to-skin contact. For more detail, read our guide on can you get STDs while using a condom.
• Attend follow-up testing — A test of cure or repeat test after treatment can confirm that the infection has been cleared and identify any reinfection early.
• Communicate openly — Discussing sexual health openly with partners — including testing history and STI status — supports informed decision-making for both parties.

Should You Retest After Treatment?

Retesting after STI treatment is an important part of sexual health management and is recommended in several circumstances:

Test of Cure

For some infections — particularly gonorrhoea — a test of cure may be recommended to confirm that the treatment has successfully cleared the infection. This is especially relevant given concerns about antibiotic resistance.

Repeat Testing at Three Months

UK sexual health guidelines recommend repeat testing for chlamydia approximately three months after treatment, particularly for individuals under 25 or those considered at higher risk of reinfection. This is because reinfection rates for chlamydia are significant, and early detection of reinfection allows prompt retreatment.

Symptom-Based Retesting

If you develop new or persistent symptoms after treatment, retesting is advisable regardless of the infection type or the time since treatment. Symptoms after treatment could indicate reinfection, treatment failure, or a different condition that requires assessment.

For information on how quickly results are returned, see our guide on how long do STI test results take.

What If You Test Positive Again?

Receiving a positive STI result after previous treatment can be frustrating, but it is a common experience and there is no reason for shame or self-blame.

A repeat positive result most commonly indicates reinfection rather than treatment failure — particularly if you completed your prescribed treatment and adhered to the advised waiting period. Your GP or sexual health clinician will be able to assess your situation and determine the most appropriate treatment.

Key points to remember:

• Reinfection does not mean your previous treatment failed — it means you have been exposed again.
• Discuss the result with your GP or sexual health clinician — they can help establish whether the result represents reinfection, treatment failure, or a different issue.
• Partner notification is important — informing sexual partners allows them to be tested and treated, breaking the cycle of transmission.
• There is no judgement attached — STI reinfection is a clinical reality, not a moral failing. Healthcare professionals are there to help, not to judge.

Treatment for a repeat infection follows the same principles as treatment for a first infection, and the prognosis is the same.

Frequently Asked Questions

Can you get chlamydia twice?

Yes. Chlamydia does not produce lasting immunity, so you can get it again after successful treatment if you are re-exposed. Reinfection is common, which is why partner treatment and follow-up testing are recommended.

Can gonorrhoea come back after antibiotics?

Yes. If you are exposed to gonorrhoea again after treatment, you can become reinfected. Gonorrhoea treatment clears the existing infection but does not prevent future infections. Antibiotic resistance is a separate concern that relates to treatment effectiveness, not reinfection likelihood.

Does having herpes once mean you're immune?

No. Herpes is a lifelong infection — the virus remains in the body after the initial episode and can cause recurrent outbreaks. These are reactivations of the existing virus, not new infections. However, you are not immune to acquiring a different strain of herpes through new exposure.

Can you pass an STI back and forth?

Yes. If one partner is treated but the other is not, the untreated partner can re-transmit the infection. This is sometimes referred to as "ping-pong" infection and is a common cause of apparent reinfection, particularly with chlamydia and gonorrhoea. Both partners being tested and treated simultaneously is the most effective way to prevent this.

How long should you wait after treatment before sex?

The recommended waiting period varies depending on the infection and treatment. For chlamydia, the general advice is to wait at least 7 days after completing treatment. For gonorrhoea and other infections, your GP or sexual health clinician will provide specific guidance. It is important that your partner has also completed treatment before resuming sexual contact.

When Should You Seek Medical Advice?

You should seek clinical advice if you experience any of the following after STI treatment:

• Persistent symptoms — if symptoms such as discharge, pain during urination, or genital discomfort have not resolved within the expected timeframe after completing treatment
• New symptoms after treatment — the development of new symptoms following treatment may indicate reinfection, a co-infection, or another condition requiring assessment
• Severe pain — significant pelvic, abdominal, or genital pain should always be assessed promptly
• Fever — a raised temperature after STI treatment, particularly if accompanied by other symptoms, warrants clinical review

These symptoms do not necessarily indicate a serious complication, but prompt assessment ensures that any issues are identified and managed appropriately.

Confidential STI Testing & Follow-Up in the UK

If you have previously been treated for an STI and are concerned about possible reinfection, confidential appointments are available at our UK clinic. Testing decisions depend on timing, exposure, and individual history.

Whether you need a test of cure, repeat screening, or guidance on next steps, our nurse-led team provides confidential, non-judgemental testing support tailored to your circumstances. If treatment is required, we will advise you on the appropriate next steps with your GP or sexual health service. Book a confidential appointment at a time that suits you.