Summary

• Syphilis is a sexually transmitted infection (STI) that if left untreated can lead to serious health problems.
• Because it is caused by bacteria, it can be cured with antibiotics.
• There has been a big rise in syphilis infections in Australia in recent years. About half of people infected with syphilis have no symptoms or else their symptoms are very mild and similar to those from other health problems.
• The only way to know for sure whether or not you have syphilis is through having blood tests. 
• Syphilis is transmitted during sex, as well as from mother to baby during pregnancy and through blood transfusions.

Why get tested?

Primary, secondary and tertiary syphilis 

Testing for syphilis can be requested by your doctor or clinic if you:

• have an ulcer or sore on your genitals or in your throat,
• are being treated for another sexually transmitted disease, such as gonorrhoea,
• are at special risk, such as being in close contact with a known case of infectious syphilis,
• are planning a pregnancy or as part of screening during pregnancy, because left untreated, syphilis can infect and cause severe illness to the developing baby, or
• have non-specific symptoms that suggest you could have syphilis.

Syphilis is classified in stages:

• Primary syphilis – when you are first infected you may have sores around your genital area or mouth that clear up within a few weeks. These are often painless and can go unnoticed.
• Secondary syphilis – your symptoms may include rashes, swollen lymph glands, fever, headaches or tiredness. These usually resolve by themselves, but if you are not diagnosed and don’t have any treatment you can be infectious for up to two or more years.
• Latent syphilis – this may develop if you go untreated. You have no symptoms, and you are not infectious, but the bacteria stay in your body for life, and you are at risk of developing tertiary syphilis.
• Tertiary syphilis – this develops in about one-third of people who have not been treated. In these cases, the syphilis bacteria damage the brain, heart, blood vessels, liver, nerves, spinal cord, eyes bones or joints. Symptoms can arise many years after your original infection and can lead to mental illness, blindness, other neurological problems, heart disease, or death.

Syphilis and pregnancy

Syphilis can cause severe complications in pregnancy and result in a premature baby, a miscarriage or stillbirth. It can also be passed on to the baby as congenital syphilis. In some cases, the baby is born without symptoms but, without treatment, they may go on to develop a range of serious health problems and can die.

Usually, these symptoms develop in the first few weeks, but sometimes they do not show up until months or years later. If you are pregnant, it is important that you are tested for syphilis at your first prenatal visit and if needed, in the final trimester. You may also be tested at the time and soon after the birth of your baby.

Types of testing

Serology tests

Syphilis is caused by the Treponema pallidum bacteria. To find out if you have syphilis, you will first need to have tests that look for the antibodies your body makes to fight the bacteria. These types of tests are called serology tests. It can take a couple of weeks after you are infected before they can show a positive result.

All the available serology tests for syphilis have limitations and no single test can confirm a diagnosis by itself. Because of this, serology tests for two types of antibodies are usually used.

These are:

• Treponemal antibody tests which detect antibodies produced by your body after you have been infected by the T. pallidum bacteria. The most often used of these are CLIA and EIA tests.
  Treponemal antibodies are detectable at about 10 to 90 days after you become infected and typically remain in your body for life. If your treponemal antibody test is positive, your sample will also undergo non-treponemal testing.
• Non-treponemal antibody tests which detect antibodies that are not specific to the T. pallidum bacteria. The most often used of these are RPR and VDRL tests.
  Non-treponemal antibodies are usually only found when you have an active infection and disappear over time whether you receive treatment or not.

If either your treponemal or non-treponemal tests are positive, your sample can be used for further, more specialised tests that may be needed to make your diagnosis.

Your antibody test results together with the history you provide your doctor will help work out what stage of the disease you may be in and will help decide what treatment will be appropriate.

PCR testing

If you have primary syphilis and a swab can be taken from a sore or ulcer, a PCR test can be performed. This detects the DNA of the T. pallidum bacteria and is an extremely accurate test. A positive test shows that you have a current infection. In the early stages of the disease, this test can be positive before antibodies are produced. However, because these sores are often painless, they can go unnoticed and the opportunity to test them is missed. If you have any symptoms at all that could be primary syphilis it is important to seek medical advice. Both PCR testing and syphilis serology tests can be performed at the same time.

If you have tertiary syphilis, you may be asked to have a procedure to take a sample of the fluid from around your spinal cord called cerebrospinal fluid (CSF). This can be tested using PCR.

Having the test

Sample

• Blood.
• Swab or scraping of an ulcer.
• Occasionally CSF – fluid from around the spinal cord.

Any preparation?

None.

Your results

The results of treponemal and non-treponemal tests are given as positive or negative.

Non-treponemal tests are more likely to give false positive results (a positive result when you are not infected) than the treponemal tests because they can be affected by other health conditions.

In treponemal tests, if the result is negative, it is extremely unlikely that you have syphilis. However, in the first two weeks after infection, all test results may be negative, so you may need further testing in two to four weeks.

If the treponemal test result is positive, and it unlikely that you have been infected previously with syphilis in the past, other syphilis specific tests will be carried out.

Treatment

Syphilis is usually treated with the antibiotic penicillin but other antibiotics can be used if you are allergic. New infections can be cured easily. A longer treatment is needed if you have been infected for more than two years or if it is unsure when you were infected. Follow-up blood testing is usually done after treatment to make sure the infection has resolved. Someone who has been previously treated can become re-infected with syphilis if they are exposed again.

Any more to know?

Newborns, especially premature and low birthweight infants and those born to a diabetic mother, are often monitored during the first few days of life for neonatal hypocalcaemia. This can occur because of an immature parathyroid gland and doesn't always cause symptoms. The condition may resolve itself or may require treatment with calcium given orally or by injection.

Questions to ask your doctor

The choice of tests your doctor makes will be based on your medical history and symptoms. It is important that you tell them everything you think might help.

You play a central role in making sure your test results are accurate. Do everything you can to make sure the information you provide is correct and follow instructions closely.

Talk to your doctor about any medications you are taking. Find out if you need to fast or stop any particular foods or supplements. These may affect your results. Ask:

• Why does this test need to be done?
• Do I need to prepare (such as fast or avoid medications) for the sample collection?
• Will an abnormal result mean I need further tests?
• How could it change the course of my care?
• What will happen next, after the test?

More information

Pathology and diagnostic imaging reports can be added to your My Health Record.

You and your healthcare provider can now access your results whenever and wherever needed. Get further trustworthy health information and advice from healthdirect.