The modern diagnosis of syphilis.

After briefly outlining the natural history of syphilitic infection, the authors review in detail the diagnosis of syphilis in the various stages of the disease and discuss the relative value at each stage of the commonly used serological tests and the Treponema pallidum immobilization (TPI) test. In their conclusions, they remark that the TPI test should be used with discretion and not as a matter of routine with all sera. Owing to its complexities and to the lengthy procedure involved, it is better suited for use with "problem" sera, for instance, sera from expectant mothers suspected of being acute non-treponemal reactors, or sera from persons with latent syphilis.