This web page was produced as an assignment for an undergraduate course at Davidson College.

What is Syphilis?

Syphilis is a sexually transmitted infection (STI) caused by the bacteria Treponema pallidum.

The most common way to initiate infection is transmission during vaginal, anal, or oral sex.

The bacteria is passed from infected skin or mucous membranes. The bacteria is most commonly transmitted though the mucous membranes around the genital region or urinary system. Mucosal transmission is often noticed during the seconday stage of syphilis infection. Infection can also occur around the area of the lips, mouth, or anus. The open sores (chancres) that develop are usually the first symptoms of infection and appear during the primary stage of syphilis infection. Infection can also occur from sharing needles during intrevenous drug use with an infected person.

Syphilis can also be passed from mother to infant through the placenta during pregnancy or delivery. This type of infection is called congenital syphilis.

The bacteria is extremely fragile however and cannot be spread through casual contact. This means you cannot contract syphilis from toilet seats, door knobs, swimming pools, hot tubs, bathtubs, shared clothing, or eating utensils.

Syphilis has an incubation period (the time between exposure to the bacteria and the development of the first symptom) that ranges from 10 to 90 days, however it has been seen to have an average incubation period of 21 days.

Syphilis has a contagious period as well which can occur on and off for many years, or during sexual intercourse, or through open sores or a skin rash when the actual bacteria is present.

Syphilis has no prejuidice and will infect whomever it comes into contact with. However, Syphilis has been known to disproportionately affect African Americans. Primary and Secondary stages of syphilis have greatly decreased throughout the United States by 90% from 1990 to 2000. Unfortunately, an increased number of syphilis cases recently happened throughout the gay community through male to male sexual intercourse from 2000 to 2002. From 2000 to 2004, the number of syphilis cases increased by almost 3,000 infected people. It has also been found that syphilis and HIV (Human Immunodeficiency Virus) have a strong correlation. Syphilis increases the risk of both transmittance and getting infected with HIV.


Return to My Home Page

Any questions, comments, or concerns please email at

Davidson College Home Page