Syphilis is a bacterial infection that is usually passed on through having sex with someone who is infected.
The bacteria that cause syphilis are called Treponema pallidum. They can enter your body if you have close contact with an infected sore, normally during vaginal, anal or oral sex or by sharing sex toys with someone who is infected.
Pregnant women can pass the condition on to their unborn baby, which can cause stillbirth or death of the baby shortly after labour. It may also be possible to catch syphilis if you are an injecting drug user and you share a needle with somebody who is infected.
Syphilis also cannot be spread by using the same toilet, clothing, cutlery or bathroom as an infected person, as the bacteria cannot survive for long outside the human body.
Three stages of disease
The symptoms of syphilis develop in three stages, described below.
- Stage 1 (primary syphilis) – Symptoms of syphilis begin with a painless but highly infectious sore on the genitals or sometimes around the mouth. If somebody else comes into close contact with the sore, typically during sexual contact, they can also become infected. The sore lasts two to six weeks before disappearing.
- Stage 2 (secondary syphilis) – Secondary symptoms, such as a skin rash and sore throat, then develop. These symptoms may disappear within a few weeks, after which you experience a latent (hidden) phase with no symptoms, which can last for years. After this, syphilis can progress to its third, most dangerous stage.
- Stage 3 (tertiary syphilis) – Around a third of people who are not treated for syphilis will develop tertiary syphilis. At this stage, it can cause serious damage to the body.
The primary and secondary stages are when you are most infectious to other people. In the latent phase (and usually around two years after becoming infected), syphilis cannot be passed on to others but can still cause symptoms.
What to do
If you suspect you have syphilis, visit a sexual health clinic as soon as possible. The earlier syphilis is treated, the less chance there is of serious complications.
If diagnosed early, syphilis can be easily treated with antibiotics, usually penicillin injections.
However, if it is not treated, syphilis can progress to a more dangerous form of the disease and cause serious conditions such as stroke, paralysis, blindness or even death.
It is estimated that people with syphilis are three to five times more likely to catch HIV. This is because the genital sores caused by syphilis can bleed easily, making it easier for the HIV virus to enter the blood during sexual activity.
Infection with both HIV and syphilis can be serious because syphilis can progress much more rapidly than normal.
The only guaranteed way to prevent a syphilis infection is to avoid sexual contact or to have sexual contact only with a faithful partner who has been tested and does not have the infection.
You can reduce your risk of catching syphilis and other sexually transmitted infections (STIs) by:
- using a condom during vaginal, oral and anal sex
- using a dental dam (square of plastic) during oral sex
- avoiding sharing sex toys
The only guaranteed way to prevent a syphilis infection is to avoid sexual contact or only to have sexual contact with a faithful partner who has been tested and is not infected.
Condoms can reduce your risk of catching syphilis, but cannot prevent it altogether. You can still catch syphilis if your mouth makes contact with a sore on an infected person’s anus or vagina, for example.
It is important not only to use a condom during vaginal, oral and anal sex, but also consider using a dental dam (square of plastic) when your mouth makes contact with your partner’s vagina or anus. This will reduce your risk of any sexually transmitted disease (STI), not just syphilis.
Avoid sharing sex toys. If you do share them, wash them or cover them with a condom before each use.
Sexual penetration or ejaculation does not need to take place for syphilis to spread.
If you are an injecting drug user, do not use other people’s needles.