Syphilis: an update on this dreaded disease

While men used to be the only ones affected, women now have to be extra vigilant: syphilis affects everyone, young and old.

What is it?

Syphilis is an infection caused by a microbe (bacterium) called treponema pallidum. Between 2009 and 2011, the number of infected people in Quebec increased by 60%! Most of these are men who have sex with men, but women are also affected. According to the Ministry of Health and Social Services, there were 25 new cases in Quebec in 2011, whereas between 1998 and 2002, there were one or two per year.

How is it transmitted?

Syphilis is contracted during sexual relations (oral, genital or anal) with an infected person in the contagious phase. A pregnant woman can infect her foetus. The disease can also be transmitted, albeit rarely, through the exchange of needles or contact with a skin lesion.

Without treatment, syphilis progresses in five stages. It is infectious in the primary, secondary and early latent stages (less than one year). During the early latent and late latent stages, it may progress to the tertiary stage.


The period between infection and onset of symptoms varies from 10 to 90 days. However, not all syphilitic patients show signs of the disease.

The most common manifestation of syphilis is a chancre (a very superficial ulcer) at the site where the bacteria entered the body – usually the genitals, mouth, vagina or rectum. It may be associated with lymph nodes in the groin. In the secondary stage, there is hair loss, rashes all over the body, inflammation of the lymph nodes, and muscle and joint pain.

In the primary and secondary stages, the symptoms often resolve without treatment, but the person remains contagious and the infection progresses.


Late syphilis manifests itself 10 to 20 years after infection with damage to the brain, heart, blood vessels and bones. It can eventually lead to death. In newborns infected at birth, the disease can cause birth defects and death. Syphilitics with genital ulcers are three to five times more likely to become infected with HIV than those without.


When a chancre is present, secretions can be examined under a microscope for treponema pale. However, this test is only available in specialised centres. In the advanced stages of the disease and during the latency phase, a blood test can confirm the diagnosis. Spontaneous healing of the chancre makes blood tests difficult to interpret, so they must be repeated.

How is it treated?

Syphilis is very well treated with penicillin injections. People who are allergic to it can use other antibiotics that are equally effective. It is important to follow the treatment completely. Blood tests every six months for two years monitor recovery.