[Improvement of symphilis screening in blood donors by TPHA test (author's transl)].

The introduction of the TPHA test in syphilis screening of blood units donated at the Heidelberg University blood bank resulted in an increase of positive test results from 0.16 precent to 0.64 percent at the first donation. Due to the high specificity of the TPHA and (FTA-Abs) test the number of doubtful and unspecific reaction results was significantly reduced. The result "TPHA and CMT reactive" indicates syphilis to be treated. From 1967--1978 this figure (0.06%--0.07%) has remained unaltered, indicating that the incidence of syphilis among blood donors has not increased. Using the TPHA test it was possible to detect blood donors with a history of syphilis, a group which could not be identified in the past. It is characterized by the reaction pattern "TPHA reactive, CMT not reactive" and is three times as frequent among our donors as the seroreactive group identified by CMT only. If fresh or unsufficiently treated cases of syphilis can be excluded, these results indicate that the individual has had a syphilis sometimes in the past. Application of the TPHA test in blood donor care reduces the risks of blood transfusion and improves the control of venereal diseases as required by law.