What is the primary antigen detected by the FTA-ABS test?

What is the primary antigen detected by the FTA-ABS test?

• A. Treponema pallidum
• B. Reiter strain of T. pallidum
• C. HIV-1
• D. HIV-2

Answer: (A)

The FTA-ABS (Fluorescent Treponemal Antibody Absorption) test is primarily designed to detect antibodies to Treponema pallidum, the causal agent of syphilis. This is a treponemal test, which means it specifically identifies antibodies produced in response to infection with this particular bacterium. The significance of detecting Treponema pallidum through the FTA-ABS test lies in its high specificity, which allows it to confirm syphilis infection, especially after a positive non-treponemal test (like VDRL or RPR) is obtained. The antibodies detected by this test are not present in other types of infections, making this a crucial tool in diagnosing syphilis accurately. While other options listed pertain to other pathogens or strains, such as various types of HIV or different strains of Treponema, they do not relate to what is specifically measured by the FTA-ABS test. The focus is exclusively on Treponema pallidum, which is why this answer is the most accurate representation of the primary antigen detected by the test.

The FTA-ABS (Fluorescent Treponemal Antibody Absorption) test is primarily designed to detect antibodies to Treponema pallidum, the causal agent of syphilis. This is a treponemal test, which means it specifically identifies antibodies produced in response to infection with this particular bacterium.

The significance of detecting Treponema pallidum through the FTA-ABS test lies in its high specificity, which allows it to confirm syphilis infection, especially after a positive non-treponemal test (like VDRL or RPR) is obtained. The antibodies detected by this test are not present in other types of infections, making this a crucial tool in diagnosing syphilis accurately.

While other options listed pertain to other pathogens or strains, such as various types of HIV or different strains of Treponema, they do not relate to what is specifically measured by the FTA-ABS test. The focus is exclusively on Treponema pallidum, which is why this answer is the most accurate representation of the primary antigen detected by the test.