Syphilis, once a cause of devastating
epidemics, can be effectively diagnosed and treated with antibiotic
therapy. In 1996, 11,387 cases of primary and secondary syphilis
in the United States were reported to the U.S. Centers for
Disease Control and Prevention. Although treatment is available,
the early symptoms of syphilis can be very mild, and many
people do not seek treatment when they first become infected.
Of increasing concern is the fact that syphilis increases
the risk of transmitting and acquiring the human immunodeficiency
virus (HIV) that causes AIDS.
Syphilis is a sexually transmitted
disease (STD) caused by a bacterium called Treponema pallidum.
The initial infection causes an ulcer at the site of infection;
however, the bacteria 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 one to two years. In its late stages, untreated
syphilis, although not contagious, can cause serious heart
abnormalities, mental disorders, blindness, other neurologic
problems, and death.
The bacterium spreads from the initial
ulcer of an infected person to the skin or mucous membranes
of the genital area, the mouth, or the anus of a sexual partner.
It also can pass through broken skin on other parts of the
body. The syphilis bacterium is very fragile, and the infection
is almost always spread by sexual contact. In addition, a
pregnant woman with syphilis can pass the bacterium to her
unborn child, who may be born with serious mental and physical
problems as a result of this infection. But the most common
way to get syphilis is to have sex with someone who has an
active infection.
Symptoms
The first symptom of primary
syphilis is an ulcer called a chancre ("shan-ker").
The chancre can appear within 10 days to three months after
exposure, but it generally appears within two to six weeks.
Because the chancre may be painless and may occur inside
the body, it may go unnoticed. It usually is found on the
part of the body exposed to the partner’s ulcer, such as
the penis, the vulva, or the 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 progress to chronic
stages.
Secondary syphilis is often
marked by a skin rash that is characterized by brown sores
about the size of a penny. The rash appears anywhere from
three to six weeks after the chancre appears. While the
rash may cover the whole body or appear only in a few areas,
the palms of the hands and soles of the feet are almost
always involved. Because active bacteria are present in
these 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, as well
as 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 one to two years.
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 no further consequences
of the disease. Approximately one-third of those who have
secondary syphilis, however, 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, the final
stage, can result in mental illness, blindness, other neurologic
problems, heart disease, and death.
Neurosyphilis: Syphilis
bacteria frequently invade the nervous system during the
early stages of infection, and approximately 3 to 7 percent
of persons with untreated syphilis develop neurosyphilis.
Some persons 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 patients
develop seizures. Patients whose blood vessels are affected
may develop symptoms of stroke with resulting numbness,
weakness, or visual complaints. In some instances, the time
from infection to developing neurosyphilis may be up to
20 years. Neurosyphilis may be more difficult to treat and
its course may be different in people with HIV infection.
Diagnosis
Syphilis has sometimes been called
"the great imitator" because its early symptoms are similar
to those of many other diseases. Sexually active people
should consult a doctor about any suspicious 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
have not also acquired syphilis.
There are three ways to diagnose
syphilis: a doctor's recognition of its signs and symptoms;
microscopic identification of syphilis bacteria; and blood
tests. The doctor usually uses these approaches together
to detect syphilis and decide upon the stage of infection.
To diagnose syphilis by identifying
the bacteria, the doctor takes a scraping from the surface
of the ulcer or chancre, and examines it under a special
"darkfield" microscope to detect the organism itself. Blood
tests also provide evidence of infection, although they
may give false- negative results (not show signs of infection
despite its presence) for up to three months after infection.
False-positive tests 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.
The blood-screening tests most
often used to detect evidence of syphilis are the VDRL (Venereal
Disease Research Laboratory) test and the RPR (rapid plasma
reagin) test. The false-positive results (showing signs
of infection when it is not present) occur in people with
autoimmune disorders, certain viral infections, and other
conditions.
Therefore, a doctor will administer
a confirmatory blood test when the initial test is positive.
These tests include the fluorescent treponemal antibody-absorption
(FTA-ABS) test that can accurately detect 70 to 90 percent
of cases. Another specific test is the T. pallidum hemagglutination
assay (TPHA). These tests detect syphilis antibodies (proteins
made by a person's immune system to fight infection). They
are not useful for diagnosing a new case of syphilis in
patients who have had the disease previously because once
antibodies are formed, they remain in the body for many
years. These antibodies, however, do not protect against
a new syphilis infection. In some patients with syphilis
(especially in the latent or late stages), a lumbar puncture
(spinal tap) must be done to check for infection of the
nervous system.
Treatment
Syphilis usually is treated with
penicillin, administered by injection. Other antibiotics
can be used for patients allergic to penicillin. A person
usually can no longer transmit syphilis 24 hours after beginning
therapy. 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.
Persons with neurosyphilis may need to be retested for up
to two 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 reversed.
Effects of Syphilis
in Pregnant Women
It is likely that an untreated
pregnant woman with active syphilis will pass the infection
to her unborn child. About 25 percent of these pregnancies
result in stillbirth or neonatal death. Between 40 to 70
percent of such pregnancies will yield a syphilis-infected
infant.
Some infants with congenital syphilis
may have symptoms at birth, but most develop symptoms between
two weeks and three months later. These symptoms may include
skin sores, rashes, fever, weakened or hoarse crying sounds,
swollen liver and spleen, yellowish skin (jaundice), anemia,
and various deformities. Care must be taken in handling
an infant with congenital syphilis because the moist sores
are infectious.
Rarely, the symptoms of syphilis
go undetected in infants. As infected infants become older
children and teenagers, they may develop the symptoms of
late-stage syphilis including damage to their bones, teeth,
eyes, ears, and brain.
Prevention
The open sores of syphilis may
be visible and infectious during the active stages of infection.
Any contact with these infectious sores and other infected
tissues and body fluids must be avoided to prevent spread
of the disease. As with many other STDs, methods of prevention
include using condoms during sexual intercourse. Screening
and treatment of infected individuals, or secondary prevention,
is one of the few options for preventing the advance stages
of the disease. Testing and treatment early in pregnancy
is the best way to prevent syphilis in infants and should
be a routine part of prenatal care.
Research
Developing better ways to diagnose
and treat syphilis is an important research goal of scientists
supported by the National Institute of Allergy and Infectious
Diseases (NIAID). New tests are being developed that may
provide better ways to diagnose syphilis and define the
stage of infection.
In an effort to stem the spread
of syphilis, scientists are conducting research on a vaccine.
Molecular biologists are learning more about the various
surface components of the syphilis bacterium that stimulate
the immune system to respond to the invading organism. This
knowledge will pave the way for development of an effective
vaccine that can ultimately prevent this STD.
A high priority for researchers
is development of a diagnostic test that does not require
a blood sample. Saliva and urine are being evaluated to
see whether they would work as well as blood. Researchers
also are trying to develop other diagnostic tests for detecting
infection in babies.
Another high research priority
is the development of a safe, effective, single-dose oral
antibiotic therapy for syphilis. Many patients do not like
getting an injection for treatment, and about 10 percent
of the general population is allergic to penicillin.
Recently, the genome of this organism
has been sequenced. The sequence represents an encyclopedia
of information about the organism. Clues as to how to diagnose,
treat, and vaccinate against syphilis have been identified
already and are fueling intensive research efforts in this
ancient but intractable disease.
.gif)
