What is syphilis?
Syphilis is a sexually transmitted infection (STD), once
responsible for devastating epidemics. It is caused by a
bacterium called Treponema pallidum
. The rate of
primary and secondary syphilis in the United States declined
by 89.2 percent from 1990 to 2000. The number of cases rose,
however, from 5,979 in 2000 to 6,103 in 2001. The U.S.
Centers for Disease Control and Prevention reported in
November 2002 that this was the first increase since 1990.
As of 2010, the incidence of new cases each year was
reported as 14,000.
Of increasing concern is the fact that syphilis increases
by 3- to 5-fold the risk of transmitting and acquiring HIV
(human immunodeficiency virus), the virus that causes AIDS
(acquired immunodeficiency syndrome).
How is syphilis transmitted?
The syphilis bacterium is very fragile, and the infection is
almost always transmitted by sexual contact with an infected
person. The bacterium spreads from the initial ulcer (sore)
of an infected person to the skin or mucous membranes
(linings) of the genital area, mouth, or anus of an
uninfected sexual partner. It also can pass through broken
skin on other parts of the body.
In addition, a pregnant woman with syphilis can pass
to her unborn child, who may be born with serious mental and
physical problems as a result of this infection.
What are the symptoms of syphilis?
The initial infection causes an ulcer at the site of
infection. The bacteria, however, move throughout the body,
damaging many organs over time. Medical experts describe the
course of the disease by dividing it into four
stages-primary, secondary, latent, and tertiary (late). An
infected person who has not been treated may infect others
during the first two stages, which usually last 1 to 2
years. In its late stages, untreated syphilis, although not
contagious, can cause serious heart abnormalities, mental
disorders, blindness, other neurologic problems, and death.
The first symptom of primary syphilis is an ulcer called a
chancre ("shan-ker"). The chancre can appear within 10 days
to 3 months after exposure, but it generally appears within
2 to 6 weeks. Because the chancre may be painless and may
occur inside the body, the infected person might not notice
it. It usually is found on the part of the body exposed to
the infected partner's ulcer, such as the penis, vulva, or
vagina. A chancre also can develop on the cervix, tongue,
lips, or other parts of the body. The chancre disappears
within a few weeks whether or not a person is treated. If
not treated during the primary stage, about one-third of
people will go on to the chronic stages.
A skin rash, with brown sores about the size of a penny,
often marks this chronic stage of syphilis. The rash appears
anywhere from 3 to 6 weeks after the chancre appears. While
the rash may cover the whole body or appear only in a few
areas, it is almost always on the palms of the hands and
soles of the feet.
Because active bacteria are present in the sores, any
physical contact-sexual or nonsexual-with the broken skin of
an infected person may spread the infection at this stage.
The rash usually heals within several weeks or months.
Other symptoms also may occur, such as mild fever,
fatigue, headache, sore throat, patchy hair loss, and
swollen lymph glands throughout the body. These symptoms may
be very mild and, like the chancre of primary syphilis, will
disappear without treatment. The signs of secondary syphilis
may come and go over the next 1 to 2 years of the disease.
If untreated, syphilis may lapse into a latent stage during
which the disease is no longer contagious and no symptoms
are present. Many people who are not treated will suffer
from no further signs and symptoms of the disease.
Approximately one-third of people who have had secondary
syphilis go on to develop the complications of late, or
tertiary, syphilis, in which the bacteria damage the heart,
eyes, brain, nervous system, bones, joints, or almost any
other part of the body. This stage can last for years, or
even for decades. Late syphilis can result in mental
illness, blindness, other neurologic problems, heart
disease, and death.
How is syphilis diagnosed?
Syphilis is sometimes called "the great imitator" because
its early symptoms are similar to those of many other
diseases. Sexually active people should consult a doctor or
other health care worker about any rash or sore in the
genital area. Those who have been treated for another STD,
such as gonorrhea, should be tested to be sure they do not
also have syphilis.
There are three ways to diagnose syphilis.
- Recognizing the signs and symptoms
- Examining blood samples
- Identifying syphilis bacteria under a microscope
The doctor usually uses all these approaches to diagnose
syphilis and decide upon the stage of infection.
Blood tests also provide evidence of infection, although
they may give false-negative results (not show signs of an
infection despite its presence) for up to 3 months after
infection. False-positive tests (showing signs of an
infection when it is not present) also can occur. Therefore,
two blood tests are usually used. Interpretation of blood
tests for syphilis can be difficult, and repeated tests are
sometimes necessary to confirm the diagnosis.
How is syphilis treated?
Unfortunately, the early symptoms of syphilis can be very
mild, and many people do not seek treatment when they first
Doctors usually treat patients with syphilis with
penicillin, given by injection. They use other antibiotics
for patients allergic to penicillin. A person usually can no
longer transmit syphilis 24 hours after starting treatment.
Some people, however, do not respond to the usual doses of
penicillin. Therefore, it is important that people being
treated for syphilis have periodic blood tests to check that
the infectious agent has been completely destroyed.
People with neurosyphilis may need to be retested for up
to 2 years after treatment. In all stages of syphilis,
proper treatment will cure the disease. But in late
syphilis, damage already done to body organs cannot be
Can syphilis cause other
Syphilis bacteria frequently invade the nervous system
during the early stages of infection. Approximately 3 to 7
percent of persons with untreated syphilis develop
neurosyphilis, a sometimes serious disorder of the nervous
system. In some instances, the time from infection to
developing neurosyphilis may be up to 20 years.
Some people with neurosyphilis never develop any
symptoms. Others may have headache, stiff neck, and fever
that result from an inflammation of the lining of the brain.
Some people develop seizures. People whose blood vessels are
affected may develop symptoms of stroke with numbness,
weakness, or visual problems. Neurosyphilis may be more
difficult to treat, and its course may be different, in
people with HIV infection or AIDS.
Note: All information is based upon
materials published by the National Institute of Allergy and
Infectious Diseases (NIAD) and the U. S. Centers for Disease