Treponema Pallidum Hemagglutination (TPHA) Test

The TPHA test is a blood test used to detect Treponema pallidum, the bacteria that causes syphilis. It is a confirmatory test for syphilis, meaning it is used after an initial screening test (such as VDRL or RPR) to confirm the infection.

Why is the TPHA Test Done?

✅ To confirm syphilis infection after a positive screening test
✅ To check for past or current syphilis infection
✅ To monitor syphilis treatment response

How Does the TPHA Test Work?

The test detects antibodies against Treponema pallidum in the blood. Since these antibodies remain in the body for life, a positive TPHA does not distinguish between a past or current infection—additional tests are needed.

Interpreting TPHA Results

🔴 Positive TPHA (+):

• You have syphilis, either a current or past infection.
• Further tests (like FTA-ABS or syphilis titers) are needed to determine if the infection is active and requires treatment.

⚪ Negative TPHA (-):

• No syphilis infection.
• However, if symptoms are present, retesting may be needed, as antibodies take time to develop.

🟡 Weakly Positive TPHA:

• May indicate early syphilis or a false positive (e.g., autoimmune conditions).
• A repeat test or further confirmatory testing is required.

Additional Syphilis Tests

1. VDRL (Venereal Disease Research Laboratory) or RPR (Rapid Plasma Reagin) – Used for screening and monitoring treatment progress.
2. FTA-ABS (Fluorescent Treponemal Antibody Absorption Test) – Another confirmatory test for syphilis.

Next Steps if TPHA is Positive?

1. Consult a doctor for further evaluation.
2. Additional tests (VDRL/RPR) to check if the infection is active.
3. If confirmed, penicillin antibiotics are the standard treatment.