Testing for syphilis.

Syphilis remains an important public health problem of growing proportions despite effective means of prevention and therapy. Clinical staging is difficult. The diagnosis is complicated by the lack of an easy culture method. History, clinical findings, and the detection of spirochetes in tissue serve as the basis for diagnosis. Simple nontreponemal tests are available for screening, and more difficult treponemal tests are used for confirmation. False-positive test results are more common with the reaginic tests but are also seen with the specific antitreponemal tests. The diagnosis of central nervous system syphilis is imprecise and is of particular importance in HIV-positive individuals. HIV infection has complicated the diagnosis of syphilis with serologic testing, although the current tests are generally adequate. Follow-up testing after treatment is used to confirm a therapeutic response. New diagnostic tests, including monoclonal antibody staining and the polymerase chain reaction, may ultimately assist in the diagnosis of this ancient disease that still has major health implications in the modern world.