Laboratory tests for syphilis are divided into two parts: screening tests and confirmatory tests, which are positive and negative to determine whether you have syphilis.
Screening tests for spirochetes, such as enzyme immunoassay (EIA) or chemiluminescent immunoassay (CLIA), are performed first. If the screening test is positive, a confirmatory spirochete test is performed, usually the Treponema pallidum particle agglutination (TPPA) test. If both of these tests are positive, the diagnosis of syphilis infection is confirmed.
Thereafter, a rapid plasma reactin ring card test (RPR) is used to detect disease activity and assess efficacy.
The diagnosis of syphilis is based on a combination of medical history, laboratory tests, and physical signs, and it is recommended that a doctor be consulted after high-risk or sexually inappropriate behavior.