Last updated: May 2020
Syphilis is a sexually transmitted infection (STI). It is transmitted from person to person during sexual activity. This can be during oral, anal, or vaginal sex. Syphilis cannot be transmitted through casual contact like sharing utensils, toilet seals, hot tubs, hugs, or shaking hands.1 Syphilis is caused by a type of bacteria called Treponema pallidum.2
Syphilis can be cured; however, the number of syphilis cases has been increasing in recent years. Men make up over 80 percent of those with syphilis and men who have sex with men make up almost half of all cases.2,3 Although syphilis impacts many men who have sex with men, it also has been increasing among women, heterosexual men, and babies born to women with syphilis.
How is syphilis related to HIV?
It is estimated that over 40 percent of all people with syphilis also have HIV.1-4 This may be for a variety of reasons. First, HIV and syphilis can have similar methods of transmission. HIV and syphilis can both be transmitted through sexual contact. People who have unprotected sex may be at increased risk of acquiring syphilis and HIV.
Open sores that facilitate HIV transmission
Syphilis can also cause painless, open sores on the penis or inside the rectum, vagina, or mouth. Depending on the location of syphilis sores, they may not be visible during sexual contact. Contact with these sores can transmit syphilis. The open sores also make it easier for HIV to enter the body as well. This may be why there is a 2 to 5-fold increase in risk of getting HIV if exposed to both HIV and syphilis at the same time.1,3,4
What are the 4 stages of syphilis?
Syphilis has four common stages: primary, secondary, latent, and tertiary. It is possible to transmit syphilis during any stage of infection, even if obvious symptoms aren’t present.
Primary syphilis often has a single sore called a chancre. A chancre is often red, circular, and painless. It can be on the penis or inside the rectum, vagina, or mouth. Not all chancres are visible on the outside of the body. Contact with a chancre can transmit syphilis. Multiple chancres can be present in primary syphilis. The first chancre appears anywhere from 10 to 90 days after exposure and can last 3 to 6 weeks.1-3
Secondary syphilis comes after primary syphilis. People with secondary syphilis may have a rash on their palms and soles. They may also have swollen lymph nodes, fever, hair loss, or issues with their kidneys or liver. Some people may get sores or raised white bumps in their mouth or other hidden areas of the body (like the underarms or groin).1-3
Some people enter a stage called latent syphilis. This can happen at any time. People in this stage do not have many symptoms at all. However, they can still transmit the infection to others.1-3
Tertiary syphilis is the last stage of syphilis. A person with tertiary syphilis can have many life-altering symptoms. These include trouble walking, paralysis, trouble speaking, heart issues, hearing or vision loss, memory issues, emotional changes, paranoia, seizures, bladder and bowel issues, and more. It can take years after infection to progress to tertiary syphilis. Thankfully, tertiary syphilis is not as common anymore since syphilis treatment is widely available.1-3
How is syphilis treated?
Most cases of syphilis are treated with the antibiotic penicillin. Some people can be cured in as little as one dose. Other antibiotics can be used for people who cannot take penicillin. One important thing to note is that people who are cured of their syphilis can still acquire syphilis again.1,2
Some of the best ways to prevent syphilis are also ways to prevent HIV transmission. Using protection during sex and getting tested regularly for STIs can help reduce your risk. Testing, especially in groups at a higher risk (like men who have sex with men), is very important since some stages of syphilis can have few or no symptoms.
Contact with a chancre inside the body, such as inside the rectum, can still transmit syphilis. Some chancres may be in areas that cannot be completely covered by condoms or other protection. Syphilis can still be transmitted in these situations. Testing is the only way to know for sure if you or your partner have syphilis or another STI.1-4