Syphilis

What is syphilis?#

Syphilis is a sexually transmissible infection (STI) caused by a bacterium called Treponema pallidum. It can affect anyone who is sexually active.

Syphilis is passed on mainly through unprotected oral, vaginal or anal sex, and through close skin-to-skin contact. It is highly contagious when the syphilis sore (chancre) or rash is present. The incubation period ranges from about 10 days to 3 months. It can also be passed from a pregnant person to their baby during pregnancy or birth, which is called congenital syphilis.

Early treatment of syphilis is very effective. However, some people do not seek advice because they have no symptoms, or do not notice the early signs. Left untreated, syphilis can lead to chronic brain or heart disease and can be fatal. Case numbers have risen in recent years, including a re-emergence of congenital syphilis, which makes testing and treatment important.

Who is at risk?#

All sexually active people are at risk of syphilis. You may be at higher risk if you are:

• a gay, bisexual or other man who has sex with men (GBMSM), or a sexual partner of one
• someone with multiple sexual partners
• a traveller returning from regions where syphilis is common
• someone who injects drugs
• a sex worker
• someone who has been diagnosed with another STI, such as HIV, gonorrhoea or chlamydia
• part of some populations where rates are higher

Being at higher risk of syphilis also means a higher risk of HIV.

How often to get checked#

Regular sexual health check-ups are recommended for anyone who is sexually active, and these usually test for syphilis, HIV, gonorrhoea and chlamydia. How often depends on your risk:

• If you are sexually active, have a full sexual health check at least once a year.
• Men who have sex with men with one partner: at least once a year.
• Men who have sex with men with more than one partner: every 3 to 6 months, and up to 4 times a year if you have several partners.

All pregnant people should be tested at least 3 times during pregnancy: at the first antenatal visit, at 26 to 28 weeks, and at 36 weeks or birth (whichever comes first).

Symptoms#

There are three stages of syphilis. Only the first two are infectious, and symptoms vary by stage. Some people have no symptoms and do not realise they are infected.

First (primary) stage#

This stage is highly contagious and usually lasts about 4 to 12 weeks. It begins as a sore (ulcer) on an area of sexual contact, such as the genitals, anus, mouth, rectum, vagina or cervix. The sore:

• appears about 3 to 4 weeks after infection, but can appear any time between 1 and 12 weeks
• is usually a single sore, but there may be several
• is usually painless and may be hard to notice, especially in hidden areas
• usually heals completely within about 4 weeks, even without treatment

If you are not treated, you may go on to develop the second stage.

Second (secondary) stage#

This begins around 2 to 4 months after infection and may last up to 2 years. It is also highly contagious. Symptoms can include:

• a flat, red skin rash on the soles of the feet, palms of the hands, or covering the whole body
• swollen lymph nodes
• hair loss, especially of the eyebrows
• joint pain
• a flu-like illness

The rash can look like other common skin conditions, such as measles, so the diagnosis may be missed if a syphilis blood test is not done.

Third (tertiary) stage#

If still untreated, about one third of people go on to develop the third stage, which can appear 10 to 30 years after the original infection. It can affect various organs, mainly the brain and heart, and can cause severe complications. Syphilis is not infectious at this stage, but it can still be treated.

Congenital syphilis#

Congenital syphilis occurs when a pregnant person with syphilis passes the infection to their baby during pregnancy or birth. The impact depends on how long the infection was present and whether, and when, it was treated. Left untreated, syphilis in pregnancy can cause miscarriage, stillbirth, premature labour, low birth weight, or death shortly after birth.

Some babies have no symptoms at birth, while others are born with signs such as skin rashes. Early symptoms (up to 2 years of age) can include bone deformities, severe anaemia, problems with vital organs such as the liver and kidneys, jaundice, brain and nerve problems (such as vision or hearing loss), a runny nose and skin eruptions. Late symptoms (after 2 years) can include eye problems, hearing loss, dental defects and a range of skeletal problems.

How syphilis spreads#

You can catch syphilis through unprotected oral, vaginal or anal sex with someone who is in the first two stages of the infection. It also spreads through close skin-to-skin contact and is highly contagious when a sore or rash is present. It can be passed from a pregnant person to their baby, and through infected blood, although donated blood is screened.

How it is diagnosed#

A routine sexual health check-up with your doctor can detect syphilis; just ask your doctor or nurse for a test. It is easy to detect using:

• a swab test, if sores are present
• a simple blood test

Test results are normally available within about a week.

How it is treated#

Penicillin is a very effective treatment for all stages of syphilis, including congenital syphilis. Other treatments are available if you are allergic to penicillin, or you may be able to have a desensitisation procedure that safely allows penicillin to be given.

Early treatment helps prevent further complications and avoids passing the infection on to partners or to a baby during pregnancy. Avoid sexual contact until your treatment is complete. Although treatment is straightforward, repeat blood tests are important to confirm it has worked, and follow-up tests may be recommended at 3, 6 and 12 months.

Reinfection#

Having syphilis once does not protect you from getting it again. Even after successful treatment, you can be reinfected by a partner who has syphilis.

Telling partners#

It is important to let all your sexual partners, both regular and casual, know that you have syphilis. Most people will appreciate being told they may have an infection. This protects you and your partners from serious health problems and helps prevent further infection in the community.

You do not have to do this alone. Your doctor or a sexual health clinic can help, and partner notification can also be done anonymously, including by SMS, email or letter if you feel unable to speak to your partners in person.

Reducing your risk#

Ways to lower your risk of catching or passing on syphilis include:

• using condoms, including internal (female) condoms, with water-based lubricant for all types of sex
• having a full sexual health check (including syphilis, HIV, gonorrhoea and chlamydia) at least once a year, and more often if you are at greater risk
• seeking early medical advice for oral, genital or anal sores or rashes linked to recent sexual contact
• if you are pregnant or planning a family, having an STI test, as syphilis can be passed to a baby

Remember, syphilis can be spread through unprotected oral sex.

Key points#

• Early treatment of syphilis is effective.
• Some people do not seek advice because they have no symptoms, or do not notice early signs.
• All sexually active people are at risk of syphilis infection.
• There are three stages of syphilis, and only the first two are infectious.
• Penicillin is an effective treatment for all stages, with other options if you are allergic.

Where to get help#