Syphilis is a sexually transmissible infection (STI) caused by a bacterium called Treponema pallidum. It can affect both men and women. Syphilis is transmitted through close skin-to-skin contact and is highly contagious when the syphilis sore (chancre) or rash is present.
The incubation period for syphilis ranges from 10 days to three months. You can pick up syphilis through oral, vaginal or anal sex with a person who has recently become infected. It can also be spread through skin-to-skin contact if the syphilis rash is present. Syphilis can also be transmitted from mother to baby during pregnancy and at birth. This is called congenital syphilis and is rare in Australia.
Early treatment of syphilis is effective, but people may not have any symptoms or may not notice the symptoms of early syphilis and therefore may not seek medical advice.
Many years after it is acquired, untreated syphilis can be fatal or may lead to chronic brain or heart disease.
Since 2002, the number of people with infectious syphilis in Victoria has increased rapidly, mainly among gay men and other men who have sex with men.
Sexual health check-ups are recommended for people at risk. The frequency of these checks depends on the person’s STI risk. For example it is recommended that:
- men who have sex with men, and who have more than one partner, are checked every three to six months
- a man who has sex with one man (has one partner) is checked once a year.
Syphilis testing is always done as part of routine antenatal screening when a woman is pregnant.
Syphilis testing is also recommended for women who have sex with men who also have male sexual partners. It is also advisable to have a blood test for syphilis if sexual partners are from a country where there are higher rates of STIs and HIV.
Symptoms of syphilis
There are three stages of syphilis. Only the first two stages are infectious and symptoms vary according to the stage. Having symptoms of syphilis can make you more at risk of HIV infection during sexual contact.
Symptoms in the first stage of syphilis
You may miss the first stage of syphilis (four to 12 weeks)as you may have no symptoms. Or, symptoms may occur as a sore (ulcer) on the genital area (including the penis or vagina), anus or the mouth. The sore:
- may be difficult to notice
- may be in the mouth or rectum or on the vagina or cervix
- is more likely to occur as a single sore but occasionally occurs as multiple sores
- is usually painless
- appears three to four weeks after infection – however, it can occur any time between one and 12 weeks after infection
- usually heals completely within four weeks without any treatment.
If you are not treated for syphilis at this stage, you may go on to develop the second stage of the disease.
Symptoms in the second stage of syphilis
During the second stage of syphilis (up to two years), you may have:
- a flat, red skin rash on the soles of your feet or palms of your hands, or it may cover your entire body. The rash is contagious and may mimic other common skin conditions such as measles. The diagnosis may be missed if a syphilis blood test is not done
- swollen lymph nodes
- non-specific symptoms, which may include hair loss (especially of the eyebrows), pain in the joints or flu-like illness.
If you are infected with syphilis and do not seek treatment at this stage, you may develop the third stage of the infection.
Third stage of syphilis
The third stage of syphilis (which may occur five to 20 years after the initial infection) can affect various organs, especially the brain and the heart. This stage occurs in about one third of untreated people. Severe brain or heart complications may occur during this stage. Syphilis is not infectious at this point, but is still treatable.
Infants born with syphilis (passed on from their mother) are said to have congenital syphilis. They may have no symptoms at birth.
Early congenital syphilis (up to two years of age) may include symptoms such as:
- a runny nose
- skin eruptions
- bone abnormalities
- eye, liver or kidney problems.
Late congenital syphilis, which presents after two years of age, may include symptoms such as:
- a variety of skeletal problems
- dental defects
- eye problems
Syphilis is unlikely to be infectious at this time.
How syphilis is spread
Syphilis is spread (transmitted) through close skin-to-skin contact with an infected area. You can catch syphilis by having oral, vaginal or anal sex with a person who is in the first two stages of the infection. Syphilis is highly contagious when the sore or rash is present and direct contact with either can result in syphilis being transmitted from one person to another.
Although rare in Australia, pregnant women who have syphilis can pass on the infection to their unborn baby.
Syphilis can also be passed through infected blood. However, blood used in blood donations is routinely screened for syphilis in Australia.
Diagnosis of syphilis
A regular sexual health check-up with your local doctor or sexual health centre can detect syphilis using a blood test. If you are a man having sexual contact with other men (including oral sex), it is important to be screened at least twice a year. Just ask your doctor or nurse for a test. Test results are normally available within a week.
Syphilis is easy to detect using:
- a simple blood test
- a swab test, if there are sores present.
Treatment for syphilis
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 undergo a desensitisation procedure that safely allows you to be given penicillin.
Treatment early in the infection is needed to help prevent further complications and to avoid passing the infection on to sexual partners.
Avoid sexual contact until your treatment has finished.
Sexual partner notification
It is important to let your sexual partner or partners know that you have syphilis. Most people will appreciate being told they may have an infection and it is an important step in preventing further infection in the community.
Your local GP and sexual health centre can help you inform your partners. This process is called ‘partner notification’. It can be done anonymously and your confidentiality is always respected.
You can also anonymously notify your sexual partners of the need to get tested and treated for syphilis via the Let Them Know website if you feel unable to speak to them personally.
Reduce your risk of infection
Ways you can reduce your risk of catching syphilis include:
- Always have safe sex – use a condom, and water-based lubricant for all types of sex.
- Remember that syphilis may be spread through oral sex.
- If you are a gay man or a man who has sex with other men, get a syphilis test and other STI checks at least yearly, and up to four times a year if you have several partners.
- Seek early advice if you notice oral, genital or anal sores, or rashes on your body, hands or feet that you think could be related to recent sexual contact.
Where to get help
This page has been produced in consultation with and approved by:
Melbourne Sexual Health Centre
Content on this website is provided for education and information purposes only. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your doctor or other registered health professional. Content has been prepared for Victorian residents and wider Australian audiences, and was accurate at the time of publication. Readers should note that, over time, currency and completeness of the information may change. All users are urged to always seek advice from a registered health care professional for diagnosis and answers to their medical questions.