Syphilis Test (VDRL / TPHA)
Syphilis is a sexually transmitted infection caused by the bacterium Treponema pallidum. It often causes no noticeable symptoms, but if left untreated it can damage the heart, brain and other organs. In pregnancy, syphilis can cross the placenta and cause miscarriage, stillbirth or serious illness in the newborn.
At YGOPH, every pregnant woman is tested for syphilis at her first antenatal visit. The infection is easily cured with penicillin, and treating the mother early, together with her partner, prevents congenital syphilis. Testing is also offered to people with genital sores or rashes, to those diagnosed with another sexually transmitted infection, and to couples planning a pregnancy.
What are the VDRL and TPHA tests?
Two kinds of blood test are used together. The VDRL (or RPR) detects antibodies produced during active infection; its level (titre) falls after successful treatment, so it is also used to follow the response. The TPHA detects antibodies specific to the syphilis bacterium and confirms that the person has been infected at some time. Some rapid tests detect these specific antibodies in a finger-prick sample.
- At the first antenatal visit, for every pregnant woman
- Genital or mouth sores, or an unexplained skin rash
- Diagnosis of another sexually transmitted infection, including HIV
- Partners of a person diagnosed with syphilis
- Babies born to mothers with syphilis
- Follow-up after treatment
Good to know
Understanding the results
A positive VDRL with a positive TPHA usually means an infection that needs treatment. A positive TPHA with a negative VDRL often reflects an infection treated in the past, as the TPHA can remain positive for life. A positive VDRL alone may be a false positive, which can happen in pregnancy or with other illnesses, and is checked with further tests.
Treatment and follow-up
Syphilis is treated with penicillin injections, which are safe in pregnancy and also treat the baby. Partners must be tested and treated to avoid reinfection. The VDRL is repeated after treatment to confirm that the titre is falling, and babies of mothers with syphilis are examined at birth and followed by our paediatricians.