Which test is used to detect syphilis in blood?

The VDRL test, or Venereal Disease Research Laboratory test, is used to detect syphilis in blood. It is a non-treponemal test, which means it detects antibodies that are produced in response to the presence of syphilis, rather than specifically identifying the syphilis bacteria itself. The VDRL test is primarily used for screening purposes, especially in the early stages of the disease.

Although the other tests listed also play a role in the diagnosis of syphilis, they are either not as commonly used for initial screening or serve different purposes. For instance, the RPR test (Rapid Plasma Reagin test) is also a non-treponemal test similar to the VDRL test, which can be used for syphilis detection. However, it is more widely accepted and slightly more reliable in routine clinical practice compared to the VDRL test. The MHA-TP test (Microhemagglutination Assay for Treponema pallidum) is a treponemal test that specifically identifies antibodies against the Treponema pallidum bacteria, which causes syphilis, but it is typically used to confirm a diagnosis rather than as a first-line screening tool