TPHA | Syphilis Detection

TPHA (T. pallidum hemagglutination) test is a serological blood test used for the detection of syphilis, a chronic sexually transmitted infection caused by the bacterium Treponema pallidum. TPHA is a specific test that helps confirm or rule out the infection, commonly used alongside other syphilis tests (e.g., RPR, VDRL).

A positive TPHA result typically appears 3–4 weeks after infection, when the body starts producing antibodies against T. pallidum. These antibodies usually persist for a lifetime, even after successful treatment, making TPHA suitable for diagnosis but not for monitoring treatment efficacy.

Test principle: The test is based on the binding of antibodies against T. pallidum to antigen-coated red blood cells. The result is presented as positive or negative.

Recommendations:

• Recommended for individuals who have had risky sexual intercourse or have symptoms characteristic of syphilis (sores, skin rashes).
• Useful for assessing the stage of syphilis alongside other non-specific tests (RPR, VDRL).
• Prescribed for pregnant women, donors, when planning surgeries, or when evaluating causes of infertility.
• A positive TPHA requires further clinical evaluation and, if necessary, initiation of treatment.
• No specific preparation is needed for the test.