Qualitative evaluation of macroscopic flocculation tests for syphilis.

Five thousand two hundred and two sera were tested in parallel using the Rapid Plasma Reagin (RPR) Card Test, the Reagin Screen Test (RST), and the Venereal Disease Research Laboratory (VDRL) Slide Test. The fluorescent treponemal antibody absorption (FTA-ABS) test was then used to confirm the reactive specimens. This comparison study was to evaluate the RPR and the RST when used in a screening program. Of the total 5,202 samples, 199 (3.8%) were VDRL reactive, 187 (3.6%) were RPR reactive, and 183 (3.5%) were RST reactive. Of the 199 VDRL reactive, 116 (58.2%) were confirmed by the FTA-ABS, 137 (73.3%) of the 187 RPR reactives were confirmed by the FTA-ABS and of the 183 RST reactives, 115 (62.8%) were confirmed by the FTA-ABS. Included in this discussion are some testing and procedural problems encountered during the study.