caused by the bacterium Treponema pallidum.
Transmission of the bacteria usually
occurs during vaginal, anal, or oral sex. The syphilis bacteria are passed from
person to person through direct contact with:
Sores mainly occur on the external genitals, vagina,
anus, or rectum. Sores can also occur on the lips and in or around the mouth.
The bacteria most commonly enter the body through mucous membranes, usually in
the area around the genitals and urinary system.
In rare cases,
syphilis enters the body through openings in the skin, such as cuts and
scrapes, or even through wet kisses, if the infected person has a sore on the
mouth or lips. Syphilis may also be transmitted by using a needle previously
used by an infected person. Syphilis can be transmitted through a
blood transfusion. But this is very rare, because all
donated blood in the United States and Canada is screened for some
sexually transmitted infections (STIs). And syphilis
bacteria cannot survive more than 24 to 48 hours in blood stored using modern
A pregnant woman with syphilis can pass the
infection through the
placenta and infect her baby any time during pregnancy
or delivery (congenital syphilis).
Syphilis cannot be
spread through casual contact with toilet seats, door knobs, swimming pools,
hot tubs, bathtubs, shared clothing, or eating utensils.
been infected with syphilis in the past does not protect a person from
becoming infected again.
An incubation period is the time
between exposure to a disease and the first symptom. A skin
sore called a chancre is usually the first symptom of sexually transmitted syphilis. A
chancre appears between 3 weeks to 3 months after a person has been
infected with syphilis.
A person with syphilis can
easily pass the infection (is contagious) to physically intimate partners when
primary- or secondary-stage sores are present. But the person may be contagious for years, off and on, and is always contagious whenever an
open sore or skin rash from syphilis is present.