This detects antibodies to treponemal bacteria that cause syphilis, yaws, pinta and bejil.
PLEASE NOTE: ALL RESULTS AND INFORMATION PROVIDED BY HEALTH eLABS ARE INTENDED FOR GENERAL HEALTH INFORMATION PURPOSES ONLY. AS SUCH THEY ARE NOT A SUBSTITUTE FOR PROFESSIONAL MEDICAL ADVICE OR A MEDICAL EXAMINATION, AND SHOULD NOT BE USED TO DIAGNOSE, TREAT, PREVENT OR CURE ANY DISEASE, SYNDROME, OR CONDITION WITHOUT THE SUPERVISION OF A LICENSED PHYSICIAN.
NOTE: This test is used to confirm an infection with the bacteria that cause syphilis. It should not be used to screen for syphilis. For those who need testing to see whether they have been infected, please visit the Syphilis (RPR Screening & Monitor) page.
PREPARATION: No fasting or other special preparation is needed for this test.
What does this test do?
This test checks for the presence of antibodies circulating in the bloodstream to treponemal bacteria, the organisms that cause syphilis as well as other diseases such as yaws, pinta, and bejil.
Why is this important?
Syphilis is a sexually transmitted infection that, if not properly treated can result in damage to the heart, brain, skin, and bones. It can even cause death. These complications can take years or even decades to develop, and typically progress through four stages: primary, secondary, latent, and tertiary.
Typical symptoms of syphilis during the primary stage include a painless skin ulcer called a chancre, that forms at the site where the bacteria first penetrated the skin (usually around the genitals or groin).
The secondary stage occurs a few months after infection and is characterized by vague, non-specific symptoms such as fever, headache, sore throat, a decreased appetite, generalized body aches and pains, and a rash. If the rash involves the palms of the hands and the soles of the feet, then this type of pattern is relatively specific to syphilis. In fact, syphilis has been called “the Great Imitator” because these types of symptoms often mimic those associated with many other diseases.
During the latent stage – which may last years or even decades – most cases of syphilis show no symptoms, except for occasional relapses of the non-specific secondary phase symptoms.
Eventually an untreated infection may progress to the tertiary stage of syphilis, and can result in devastating damage to the liver, bones, testicles, heart, and blood vessels. Tertiary syphilis can also affect the central nervous system by causing dementia, and stroke.
Syphilis is caused by a microorganism called treponema pallidum (t. pallidum), a member of an extremely specialized class of bacteria called spirochetes. These microbes are notoriously difficult to detect on testing modalities, but once found they are relatively easy to kill with antibiotics.
Unlike many other organisms that have become resistant to penicillin, treponema pallidum remains sensitive to the drug so the treatment of most cases of syphilis remains straightforward. During its primary and secondary stages a single injection of an appropriate dose of penicillin will cure the disease, while those in the latent and tertiary stages of syphilis need three injections, given over a three week period. For those who are allergic to penicillin other oral antibiotics can be used, but with diminished success.
Quite unlike its treatment, however, the diagnosis of syphilis remains difficult even to this day, and many different screening tests have been developed over the years to detect it. If a screening test for treponema pallidum (such as the RPR) is positive, then a secondary test is used to confirm the presence of infection within the body.
That is what this test, the Fluorescent Treponemal Antibody (FTA), is for. It looks for the presence of antibodies to several different species of treponemal bacteria, including the t. pallidum that causes syphilis.
What do the results mean?
A negative result may mean that there is no infection with t. pallidum. This isn’t always the case, however – it takes 4-6 weeks after exposure for enough antibodies to be produced to become detectible by the FTA test. So if performed too soon after a suspected infection, an FTA test may be falsely negative.
Once the FTA test becomes positive however, it typically stays so for several years as the immune system continues to produce antibodies. This test has a high sensitivity at detecting antibodies in all stages of syphilis. However, the FTA test is not 100% specific for the t. pallidum that causes syphilis, and may cross react and detect antibodies to different treponemal bacteria that cause other diseases such as yaws, pinta and bejil.
Additionally, the FTA-ABS does not indicate a person’s response to antibiotic therapy, and it is not suitable for monitoring treatment. Nevertheless, a positive result is a strong indicator of syphilis infection – even in the absence of symptoms. Given the potentially devastating complications if left untreated, a positive FTA result should be followed up with your physician promptly.