If you knew anything about sexually transmitted infections (STIs), you’d know that you get Syphilis from sex.

But you might be surprised to know that sexual intercourse isn’t the only way you can get it.

Today, we’re addressing an important topic that we hear about a lot from our patients: whether Syphilis can be transmitted through saliva. Syphilis has made a comeback in recent years, so it’s important to know how to protect your health from the worst effects of this infection.

Let’s get into it.

Don’t let this very pernicious sexually transmitted disease damage your health. Get tested for Syphilis at a sexual health clinic near you.

What is Syphilis?

Syphilis is a sexually transmitted infection (STI) caused by the bacteria Treponema pallidum. This bacterial infection is known for its ability to cause serious health problems if left untreated, but it’s also highly treatable when detected early. Syphilis progresses through several stages, each with distinct symptoms, making it a complex condition to understand and manage.

Primary Syphilis

During the primary stage, the infection typically presents with painless sores (chancres) at the site of infection. This can occur around the genital, anal, or oral areas in the early stages of the infection.

Secondary Syphilis

 If the infection progresses to the secondary stage, you may experience symptoms like skin rashes, fever, sore throat, swollen lymph nodes, and muscle aches.

Latent Syphilis

Latent Syphilis follows, where the infection remains in the body without causing symptoms. Untreated Syphilis can lead to severe symptoms and life threatening complications, including damage to internal organs like the brain, heart, and nerves.

It’s important to note that many cases of Syphilis don’t present with any symptoms or can produce symptoms so minor that the infected person doesn’t notice them.

How is Syphilis transmitted?

You can transmit Syphilis through direct contact with a Syphilis sore, also known as a chancre. These sores tend to appear on the external genitals, vagina, anus, rectum, lips, or inside the mouth. The infection is most commonly spread during vaginal, anal, or oral sex with someone who has Syphilis. Syphilis can also be transmitted even if the infected person does not have visible sores or symptoms.

It’s easier to catch Syphilis if the skin gets damaged during sex. For this reason, we see it more in anal sex, or in sex that lasts a long time.

In addition to sexual contact, Syphilis can also be transmitted from mother to child during pregnancy or childbirth, a condition known as congenital Syphilis. This can lead to severe health complications for the baby, including stillbirth or developmental issues.

Although rare, Syphilis can also be spread through blood transfusions if the blood is not properly screened, but this is highly unlikely in countries with rigorous blood donation screening processes.

Can Syphilis be transmitted through kissing?

Because the mouth can be the site of infection, and because Syphilis can be transmitted through direct contact with a chancre, this means that Syphilis can be transmitted orally, resulting in an Oral Syphilis infection.

There have been cases described of Syphilis being transmitted through deep kissing, although this is extraordinarily rare and most likely only occurs through direct contact with a chancre.  

While Syphilis bacteria can be present in saliva, there isn’t much evidence to suggest that the saliva of an infectious person will transmit Syphilis to another person. Therefore, you will not catch Syphilis by coming into contact with saliva alone.

How can I avoid getting Syphilis?

Preventing Syphilis involves taking proactive steps to protect yourself and your partners.

One of the most effective ways to prevent Syphilis is to practice safe sex and avoid direct contact with Syphilis sores. However, it’s important to remember that sores may not be visible to either partner, so additional precautions may be necessary.

To minimise the risk of contracting Syphilis through oral contact, it’s crucial to be aware of any symptoms and seek regular STI testing, especially if you or your partner have had new or multiple sexual partners.

Regular STI testing is another crucial measure in preventing the spread of Syphilis. If you or your partner has had new or multiple sexual partners, getting tested regularly can help detect Syphilis early and ensure timely treatment. Open communication with your sexual partners about STI status and testing history is also essential in maintaining sexual health and preventing the transmission of infections.

Understanding Syphilis and its transmission is crucial for maintaining your sexual health. By being informed about how this infection spreads and taking proactive steps to prevent it, you can protect yourself and your partners from this infection.

What other sexually transmitted infections can be transmitted through saliva?

Syphilis isn’t the only infection that might be passed on through saliva.

Herpes

Oral Herpes can also be passed on through kissing. The Herpes Simplex Virus transmits primarily through skin to skin contact.

Once passed on, the Herpes virus embeds itself in the nerve endings near your jaw. From there, they periodically travel to the surface of the skin, causing outbreaks of cold sores.

If you perform oral sex on someone while you are having an outbreak of cold sores, you may transmit the infection to your partner’s genitals, resulting in a genital Herpes infection.

Gonorrhoea

There is also some evidence to suggest that Gonorrhoea can be transmitted between men who have sex with men through deep kissing.

Human Papillomavirus (HPV)

HPV is most commonly transmitted through vaginal, anal, and oral sex. However, in a small number of cases, the virus can be transmitted through kissing.

How can I treat Syphilis?

Syphilis is a curable bacterial infection. If you test positive, Syphilis treatment is straightforward and effective.

A course of antibiotics, usually penicillin, is prescribed to eliminate the infection. You must avoid sexual contact until your treatment is complete, and it’s essential that your sexual partners also receive treatment to prevent reinfection.

Final thoughts

If you’re sexually active and concerned about sexually transmitted diseases, we recommend getting tested with Better2Know’s Full STI Screen. This screen detects the seven most common STIS in the Middle East, including Syphilis, HIV, Chlamydia, Gonorrhoea, Hepatitis B, Mycoplasma, and Ureaplasma.

Don’t wait to take control of your sexual health. Click the button below to book your STI test and get the answers you need.

Don’t leave your sexual health to chance. Get tested with Better2Know today.

This article first appeared on 23/01/2025. Last updated 22/08/2025.

This article has been medically reviewed by Dr. Steve Chapman, 29/04/2025.