How do I prevent syphilis?

Updated on:
February 16, 2022

How is syphilis transmitted?

To talk about syphilis prevention, we first go over the different ways syphilis can be transmitted:

  • Sex with somebody who has syphilis (both penetrative and oral sex)
  • Pregnancy or childbirth
  • Sharing drug use equipment

Which methods are more likely to transmit?

Data that explores the likelihood of transmission according to each risk behaviour is challenging to come by. It relies on a variety of factors, such as frequency of behaviour, type of behavior, stage of syphilis, condom usage, etc.

When is syphilis contagious?

Syphilis is usually infectious for less than one year, during primary and secondary stages, and in the beginning of the latent stage. The symptomatic stages - primary and secondary - are the most contagious. Late latent syphilis (infection has lasted over one year) is considered to be non infectious.

Around 20-30% of those with syphilis at the latent stage have a relapse of the secondary stage of the infection. Relapses can occur several times, and when relapses no longer occur, a person is no longer contagious through contact (this does not apply to pregnancy and childbirth).

Does syphilis even stop being contagious?

When the infection has lasted over one year (late latent syphilis), it is considered to be non infectious. Once symptomatic relapses cease, syphilis is usually no longer contagious through sexual contact.

Are there cases when it’s not contagious at all?

All persons with active syphilis infection are contagious in the primary, secondary, and early latent phases.

How do I prevent myself from contracting syphilis?

Condoms (protecting the user)

Using latex or polyisoprene condoms and/or oral dams for all sexual activities, including oral sex. This type of prevention does not completely eliminate the chance of transmissions, as syphilis sores may be in uncovered regions, however consistent condom use reduces the risk.

Dental dams (protecting the user)

Although dental/oral dams do not fully prevent syphilis, their correct and consistent use can reduce your chance of getting the infection.

Pill and/or vaccination (protecting the user)

There are currently no approved pills or vaccines in Canada that can be taken to prevent syphilis before a possible exposure. The only ways to prevent syphilis is to ensure frequent STI testing, safer sex practices, and that syphilis treatment is equitably distributed when needed.

Testing & Treatment (protecting the user)

Talk to your partners about their history of STIs, and their latest STI test. If you or your partner notice any unusual discharge, a sore around the groin area or in the mouth, and/or a rash on the hands and feet , avoid having sex and speak to a health provider as soon as possible.

If you’re sexually active, pregnant, or share drug use equipment, it’s really important to ensure you’re getting tested for STIs. Getting tested frequently is one of the best tools we have to prevent transmissions.

How do I prevent myself from transmitting syphilis?

While the tools to prevent contracting syphilis are the same as the tools that will prevent you from transmitting, it is important to ensure you are not sexually active when actively infected and for the 7 days following your treatment.

  • Condoms (protecting the partner)
  • Dental dams (protecting the partner)
  • Pill and/or vaccination (protecting the partner)
  • Testing & treatment (protecting the partner)

Can you prevent syphilis 100% of the time?

Since syphilis sores can be present in areas uncovered by oral dams and condoms, there’s still a possibility of transmission when condoms are used. Taking a combined approach to prevent syphilis through STI testing, condom use, etc. can maximize your ability to prevent syphilis.


Reviewed by:
Dr. Caley Shukalek

Caley is passionate about evidence-based, patient-centred care, including telemedicine that can provide high quality care from wherever a patient may choose.

He helped create Alberta's PrEP guidelines and works as a specialist in General Internal Medicine with additional training in sexual health, including HIV and sexually transmitted infections.

He holds an Masters of Public Health from Johns Hopkins University, an MD from the University of Calgary and an MSc from the University of Alberta.