Syphilis
More details/Information for students
Definition
Statistics
Stages of infection
Transmission
Testing
Diagnosis
Treatment
Follow up
Prevention
Syphilis is a sexually transmitted disease caused by
Treponema pallidum. This organism is a type of bacterium known as a
spirochete. Syphilis is easily treated, but can have serious complications
if not treated soon after infection.
Both men and women can have syphilis, and it can be
passed from an infected pregnant woman to her unborn infant.
In recent years, less than 100 cases of syphilis have
occurred each year in South Australia. Seventy-four (89%) of these
occurred among Aboriginal people. This contrasts with gonorrhoea, where
31% of cases were among Aboriginal people, and chlamydia, where only 5% of
cases occurred among Aboriginal people. The majority of cases have
occurred in the Aboriginal population. (See Statistics
page for most recent information.)
Stages of infection
Syphilis occurs in three stages. In stages one and two a
person is infectious during sexual contact.
After an incubation period of 9 to 90 days (averaging 3 weeks),
during which time the patient may have no symptoms, the first sign may
develop.
The first stage shows as a hard, usually
painless, sore on the genitals, mouth or other point of sexual contact.
This sore usually appears three to four weeks after infection, but it can
appear any time between ten and ninety days after infection. It normally
heals completely within four weeks. Even though the symptoms disappear
without treatment, the person is infectious.
During the second stage there may be a flat, red
skin rash, hair loss, fever, lumps on the genitals or general tiredness.
These symptoms may appear two to four months after infection and last for
several weeks. If not treated, they often come back. The rash can be over
the whole body, and is very contagious.
An infected (but untreated) person may remain infectious
through sexual contact for up to two years.
The third stage may occur in up to one third of
untreated individuals. It may show as severe complications in the brain or
heart. This stage is not infectious.
Untreated syphilis in no longer infectious through
sexual contact after two years and is considered to be hidden or late
latent stage infection. There are no symptoms and nothing to
find on examination. The only abnormality is a positive blood test for
syphilis. A small number of people with latent syphilis will develop
serious complications seen in the third stage of the disease. Treatment is
available to prevent these late complications.
Because of the widespread use of antibiotics, modern-day
syphilis may not show genital symptoms, or the symptoms of secondary
syphilis.
During infectious stages, syphilis can be highly
contagious. The condition is transmitted by skin-to-skin contact with an
affected area. Sores develop on the site that has touched the infectious
area. Depending on the type of sexual contact, sores may therefore appear
on or near the genitals, lips, fingers or anus.
The traditional, preferred testing method is dark-field
microscopy. Specimens are taken from active lesions and examined directly
by a special microscope.
Blood tests should always be taken to diagnose syphilis.
These tests are complex and require expert interpretation. Serology is
used to monitor the effectiveness of treatment in syphilis.
Syphilis is diagnosed by blood test.
There are two types of tests available:
- One is more specific in diagnosing the infection.
These tests are positive in people who have been exposed to syphilis
previously. These tests can remain reactive for life, so a positive
result does not necessarily mean you currently have syphilis. Some
people with a positive result are not aware they have had syphilis
before.
-
Another test is used to
determine if the disease is active and that treatment has worked (the
level falls after successful treatment).
It can be difficult to interpret the results of syphilis
blood tests. Sometimes the tests need to be repeated. If there is any
uncertainty regarding the result, you should discuss it with an
experienced doctor.
It is important that all pregnant women have routine
antenatal screenings for syphilis.
Penicillin, given by injection, is very effective
treatment. One dose is effective but three doses are given for late latent
infection. A single injection of a long-acting penicillin that
persists in the blood for 2 to 3 weeks is the best treatment.
Some doctors suggest daily injections for this period. Even though the
symptoms improve after a single dose it is important to follow your
doctor's instructions regarding follow-up.
Other treatments are available if a person is allergic
to penicillin.
Treating a pregnant
woman cures the foetus. Some people with early syphilis may develop a mild
fever, headache, or swelling of lesions following treatment. This is
rarely serious.
Repeated blood tests are necessary for at least a year
after treatment to monitor possible treatment failure. People who have had
tertiary syphilis should be followed up for many years.
After treatment, regular blood tests are done to check
that the infection has been cured. Do not have sex until the follow-up
test indicates the treatment has worked.
Recent sex partners need to be tested and treated.
-
The use of condoms during vaginal and anal
intercourse.
-
Sexual practices other than intercourse carry less
risk of transmitting syphilis.
-
It is important that an individual who has syphilis
avoids sexual contact involving the genitals during treatment and
until a negative test result is obtained. This will aid healing and
prevent transmission.
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