Syphilis Test

Syphilis testing detects infection with the bacterium *Treponema pallidum*, which causes syphilis—a sexually transmitted infection (STI) that can progress through multiple stages if untreated. Testing helps diagnose current or past infection and guide appropriate treatment. Syphilis tests include non-treponemal (e.g., RPR, VDRL) and treponemal (e.g., FTA-ABS, TPPA) assays.

1. What Is Syphilis?

• Syphilis is a bacterial STI transmitted through direct contact with syphilitic sores, usually during sexual activity or from mother to child during pregnancy (congenital syphilis).

• The disease has four stages: primary, secondary, latent, and tertiary, each with distinct symptoms and complications.

• Early detection and treatment prevent long-term damage and transmission.

2. Types of Syphilis Tests

🔹 Non-Treponemal Tests:

• RPR (Rapid Plasma Reagin) and VDRL (Venereal Disease Research Laboratory) tests detect non-specific antibodies (reagin).

• Used for screening and monitoring treatment (titers drop with successful therapy).

🔹 Treponemal Tests:

• FTA-ABS (Fluorescent Treponemal Antibody Absorption), TPPA (Treponema pallidum Particle Agglutination), or EIA (Enzyme Immunoassay).

• Detect specific antibodies to *T. pallidum* and remain positive for life, even after treatment.

3. Why Is the Syphilis Test Performed?

• Diagnose syphilis in symptomatic individuals (e.g., genital sores, rash, swollen lymph nodes).

• Screen high-risk populations (e.g., individuals with other STIs, sex workers, pregnant women, or men who have sex with men).

• Confirm syphilis after positive screening results.

• Monitor treatment response using non-treponemal titers.

4. Interpreting Test Results

🔹 Positive Non-Treponemal and Treponemal Tests:

• Indicates active or past syphilis infection.

• Requires clinical correlation and possibly additional staging tests.

🔹 Positive Treponemal Test and Negative Non-Treponemal Test:

• May indicate past treated syphilis or late/latent infection.

🔹 Negative Tests:

• Likely no current or past infection (note that early syphilis may yield false negatives).

5. What Can Affect Test Accuracy?

• False positives can occur in autoimmune diseases, pregnancy, HIV, or other infections.

• False negatives may happen in early syphilis, latent infection, or with the prozone effect.

• Diagnosis often requires a combination of tests and clinical history.

6. How Is the Test Performed?

• A blood sample is drawn from a vein.

• Sometimes, spinal fluid or lesion swabs are tested in advanced or congenital syphilis.

7. When to See a Doctor

🚨 Seek medical care if you:

• Have unexplained sores, rashes, or sexual exposure to syphilis.

• Are pregnant and have not been tested for syphilis.

• Need follow-up or treatment monitoring for a known diagnosis.

🔹 Key Takeaways

✅ Syphilis is a serious but curable STI if detected early.

✅ Testing involves both screening and confirmatory methods.

✅ Regular testing is important for at-risk individuals and prenatal care.