Syphilis Quick Facts

What is syphilis?
Syphilis is a sexually transmitted disease, which has been called “The Great Pretender”, as symptoms can resemble other diseases. Syphilis is primarily transmitted during sexual contact, or during pregnancy or childbirth from an infected mother to her infant (1).

What causes syphilis?
Syphilis is caused by infection with the bacterium Treponema pallidum subspecies pallidum.

What are the symptoms of syphilis?
Untreated syphilis infections have four distinct stages.

Primary syphilis is characterized by a skin lesion, called a chancre, which appears 10-90 days after infection. It can be a single chancre or multiple chancres may form (1). Chancres last 3-6 weeks and health whether or not treatment is received. If untreated, the infection progresses to the secondary stage (2).

Skin rashes and/or lesions in the mouth, vagina, or anus occur during the secondary stage of infection. Additional symptoms in the secondary stage can include fever, sore throat, hair loss, weight loss, swollen lymph glands, headaches, muscle aches, and fatigue (1). Like the primary symptoms, secondary symptoms will also disappear whether or not treatment is received. However, the syphilis infection will progress to the latent stage if adequate treatment does not occur (2).

The latent stage is not associated with any symptoms, except the syphilis-causing bacterium is still present. During the early latent stage, transmission can still occur. The latent stage can last for many years, with 15-40% of untreated individuals developing tertiary syphilis (3).

In some cases, the latent stage progresses to a potentially fatal tertiary stage. This can occur 10-30 years or more after acquiring a syphilis infection. Multiple different organ systems can be affected including the brain, nerves, eyes, heart, liver, bones, and joints.

Who is at risk of syphilis?
The primary high-risk populations for syphilis are men who have sex with men, and HIV-positive individuals. Other high-risk populations include individuals who have been incarcerated, sex workers, and members of certain racial groups (4).

How is syphilis diagnosed?
Syphilis diagnosis is by two types of laboratory analyses of a blood sample – nontreponemal and treponemal tests. Both are required for an accurate diagnosis.

How is syphilis treated?
Primary, secondary, and early latent stage syphilis (infection within 2 years) is treated with a single intramuscular dose of Benzathine penicillin G. Late latent stage syphilis (more than 2 years after original infection) requires three intramuscular doses of Benzathine penicillin G at weekly intervals (5).

1. Kent ME & Romanelli F (2008). Reexamining syphilis: an update on epidemiology, clinical manifestations, and management. Ann Pharma, 42 (2), 226-236.

2. Syphilis – CDC Fact Sheet (Detailed). (2017, January).
3. Peeling RW, et al. (2017). Syphilis. Nat Rev Dis Primers, 3(17073).
4. Schwenk TL (2016, June 9). Screening High-Risk Populations for Syphilis. NEJM Journal Watch.
5. Workowski KA & Bolan GA (2015) Sexually Transmitted Diseases Treatment Guidelines, 2015. MMWR Recomm Rep, 64 (RR-03), 1-137.