How long is syphilis contagious after treatment

Syphilis is a sexually transmitted infection (STI). If it's not treated, it can cause serious and potentially life-threatening problems.

The symptoms of syphilis are often mild and hard to notice. They tend to change over time and may come and go.

Symptoms of syphilis include:

  • small sores (ulcers) on your penis, vagina, or around your bottom (anus) – these are usually painless and you may only have one of them
  • sores in other areas, including in your mouth or on your lips, hands or bottom
  • white or grey warty growths most commonly on your penis, vagina or around your anus
  • a rash on the palms of your hands and soles of your feet that can sometimes spread all over your body – this is not usually itchy
  • white patches in your mouth
  • flu-like symptoms, such as a high temperature, headaches and tiredness
  • swollen glands
  • patchy hair loss on the head, beard and eyebrows

It can take 3 weeks or more for the symptoms of syphilis to appear after you're infected.

Sometimes the symptoms can improve or go away completely, but if you have not been treated the infection is still in your body.

This means you can still pass it on and you're at risk of getting serious problems later on.

  • you or a sexual partner have symptoms of syphilis
  • a sexual partner has told you they have syphilis or another sexually transmitted infection (STI)
  • you've recently had sex with a new partner and did not use a condom
  • you're pregnant or planning to get pregnant and think you might have syphilis
  • you've injected drugs using a needle that's been used by someone who might have syphilis

Having a test is the only way to confirm if you have syphilis. If you do, treatment will need to be started as soon as possible. Tests for STIs are free on the NHS.

You can also have a syphilis test:

  • during a pregnancy (antenatal) appointment, if you're pregnant
  • using a self-test kit – you may be able to order a kit online from your local STI testing and treatment service or buy one from a pharmacy

You use a self-test kit at home and send it to a lab to be tested.

If you have symptoms of syphilis, a doctor or nurse will check your penis, vagina and bottom (anus) for syphilis sores (ulcers). They may use a swab (like a cotton bud) to collect a fluid sample from any sores.

They'll also check the rest of your body for other signs of syphilis like a rash, sores or wart-like growths. They may also take a blood sample.

You may also have tests for other sexually transmitted infections (STIs) at the same time.

If you have syphilis, your current and any recent sexual partners will also need to be tested and treated.

The GP or sexual health clinic can advise you about contacting your sexual partners. This can be done without naming you.

Syphilis is treated with antibiotics, which you may have as injections, tablets or capsules.

Treatment may be started before your test result is known. How long you need treatment for will depend on the stage of your syphilis.

In some people, treatment can cause flu-like symptoms, such as a high temperature, headache and aching muscles. This usually lasts for up to 24 hours.

You'll need to go back to the GP surgery or sexual health clinic 6 and 12 weeks after starting treatment to be retested.

Do not have sex (vaginal, anal or oral) until you and your partner have finished treatment and tests have shown treatment has worked.

If it's not treated, syphilis can cause serious and potentially life-threatening problems including:

  • heart problems like angina, aortic aneurysm and heart failure
  • brain problems like fits (seizures), memory problems, personality changes and dementia
  • nerve problems like shooting pains, pins and needles, joint pain and gradual damage the joints
  • problems with the skin, bones, testicles, liver and any other organ

Some of these problems may not appear for many years after being infected with syphilis.

Syphilis during pregnancy

If you're pregnant and have syphilis, you can pass it on to your baby before they're born. This is known as congenital syphilis.

Having syphilis during pregnancy can also increase your risk of miscarriage, premature birth and stillbirth.

You'll be offered screening for syphilis if you're pregnant so it can be found and treated before it causes any serious problems.

The most common way of getting syphilis is by having unprotected sex (vaginal, anal or oral sex without a condom) with someone who's infected.

You can get the infection if you come into contact with an ulcer on their penis, vagina, bottom (anus), or inside their mouth.

It's also possible for syphilis to be passed on:

  • to an unborn baby during pregnancy (congenital syphilis)
  • by injecting drugs with a needle that's been used by an infected person
  • during a blood or organ transplant (this is rare as all blood and organ donations in the UK are checked for syphilis)

There are some things you can do to avoid getting syphilis and passing it on to others.

  • use a condom when you have vaginal or anal sex

  • use a condom to cover the penis or a latex or plastic square (dam) to cover the vagina if you have oral sex

  • make sure you complete treatment if you or your partner have syphilis

  • do not share sex toys (or wash and cover them with a new condom before anyone else uses them)

  • do not share needles if you inject drugs

Page last reviewed: 25 May 2022
Next review due: 25 May 2025

How long is syphilis contagious after treatment

You can be treated for syphilis before or after you test positive for it, and people choose differently depending on their circumstances.

If you decide not to take the medication:

Some people prefer not to take medication unless they know they have a disease. This is the ideal way of dealing with any condition.


If you choose this option, you need to stop having sex (and be OK with that) for three months after exposure because a syphilis test is not reliable until then.

If you decide to take the medication:

There are a few things you should keep in mind if you make this decision:

  • You might be taking the medication unnecessarily
  • You might be exposing yourself to side effects (though the risk is extremely low with a one-time dose)

It is ideal to be treated sooner rather than later but it is not an urgent matter (not an emergency). Post-exposure treatment is not extremely time-sensitive and can be given later.

Treatment will be effective if you had risky sex last night

Two doxycycline (100 mg) oral tablets taken within 24 hours of sexual intercourse may decrease the risk of syphilis acquisition by over 73%.3, 5

Primary syphilis

Syphilis can initially cause sores or ulcers around the genital area, mouth, or throat 10—90 days (average 21 days) after infection. These sores, called chancres, can be any size or shape. They are often painless, don’t bleed, and can feel like a hard button on the skin. Sometimes these sores may be internal and go unnoticed. This is called the primary stage of syphilis. If not treated, the sores usually heal and disappear after a few weeks, however, the syphilis infection remains in the body and the person is still infectious.

Secondary syphilis

Two to six months after getting infected, the secondary stage of syphilis occurs. Symptoms may include a flu-like illness, a rash on the trunk, palms, and soles of the feet, swollen glands, wart like lumps around the moist areas of the body, and hair loss. Some people also get headaches, tiredness and pains in the bones, muscles and joints. When these symptoms go the person is still infectious.

Early latent syphilis

This means that the person does not have any signs or symptoms but is infectious. The only way they would know they had syphilis is to have a blood test.

Late latent syphilis

This means the person is not infectious. The only way the person would know they have syphilis is to have a blood test.

What happens if syphilis is not treated?

If the infection is not treated, the signs and symptoms will go away, although some of them may come and go for up to a year. However, the syphilis infection still remains in the body and people can pass syphilis onto their sexual partners during this time for up to two years.

If a pregnant woman has untreated syphilis, the infection can pass, via the placenta, to her unborn baby. This can seriously affect the baby. Infection can pass from mother to baby for a much longer period than for sexual partners. It is believed to be a risk for any pregnancy for up to eight years after initial infection if that infection was not treated.

If late latent syphilis is not treated, over time (which may be many years), the syphilis infection can affect different parts of the body. It can cause problems with nerves, the brain and the large vessels near the heart.


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Safe sex is about:

  • reducing the spread of sexually transmissible infections (STIs)
  • avoiding unintended pregnancies
  • staying emotionally healthy.

The most common STIs in Australia are chlamydia, genital herpes, genital warts, trichomoniasis, gonorrhoea, Hepatitis B, syphilis and Human Immunodeficiency Virus (HIV).

STIs can be passed to sexual partners through:

  • vaginal sex
  • oral sex
  • anal sex
  • close sexual contact.

Some STIs can be passed from mother to her child during pregnancy or childbirth. They can also be spread between injecting drug users when sharing needles and/or other injecting drug equipment.

Using condoms (on the penis) reduces the risk of passing on STIs during sexual intercourse and oral sex.

Sometimes people with an STI have no symptoms. They might not be aware they have been infected and can pass on the STI during unprotected sexual intercourse and/or oral sex.

Condoms are the only form of contraception that protects against the spread of STIs. If you would like additional information on how to keep yourself safe you can talk with your doctor, Family Planning Queensland or a sexual health clinic.

Tips

  • Condoms should be used when engaging in vaginal, anal or oral sex.
  • It is advisable not to have sexual intercourse, if your sexual partner has a visible sore, ulcer or lumps on the genitals or anal area.
  • Some STIs can be passed to the lips, mouth and/or throat during oral sex. It is advisable to use condoms or dental dams for oral sex involving the vulvae or anal areas.
  • Drinking alcohol and taking other drugs may affect a person’s ability to make healthy choices. it is advisable not to engage in sexual activity, if you are not in full control of the situation.
  • Using condoms is the safest method of contraception against the spread of STIs.
  • Using sex toys also carries possible transmission risks. Where appropriate, condoms should be used in conjunction with these devices.

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