[Passive haemagglutination test in serodiagnosis of syphilis. Survey of a one-year trial in a venereal diseases prophylactic center (author's transl)].

We report here a one-year study of the reliability of the Treponema pallidum Haemagglutination Test (TPHA) in the serological diagnosis of syphilis. By comparing TPHA data with the diagnosis based on a set of grouped criteria, we were able to determine TPHA accuracy. All studies were conducted at the Antivenereal Prophylactic Center, in Nice, France, on 1,775 sera. The grouped data consisted of:--Serological Test for Syphilis (STS) using cardiolipin antigen,--medical and epidemiological records;--two specific reactions; namely the Fluorescent Antibody Test (FTA) and the Treponema Immobilisation Test (TIT). Reliability is excellent in 98.58 p. 100: the TPHA either proves syphilis or eliminates this diagnosis. The TPHA was particularly useful in investigating "problem sera" for which there existed conflicts in the grouped data. The applicability of TPHA is limited, however, in that it has low sensitivity during early primary syphilis, and it cannot be used to monitor antibodies during treatment. Nevertheless, TPHA, based on a standard specific antigen, is assured of a high place among the tools of serological diagnosis of syphilis because of its high accuracy and sensitivity, its objective and easily read results, and the simplicity of its technique.