Qualitative evaluation of the reagin screen test.

After a preliminary study of 557 sera used as a procedural training exercise, the Reagin screen test (RST) for the macroscopic detection of reagin (as an aid to detecting syphilis) was qualitatively compared to the rapid plasma Reagin (RPR) (circle) card test and Veneral Disease Research Laboratory (VDRL) slide test on 435 random portions of sera using fluorescent treponemal antibody adsorption (FTA-ABS) results as a comparative base. A comparison of total agreement (positive and negative) with the FTA-ABS results led to the following order. RPRCT (I5.5%), VDRL (79.8%), and RST (74.5%). Of the total samples shown to be reactive by the FTA-ABS procedure, the percentage of these interpreted as nonreactive (i.e., "false negative") by the procedures compared was considerably higher with the RST procedure (29.3%) than with either the RPRCT (10.9%) or the VDRL (7.1%) procedures. Minor problems encountered with procedural techniques are also mentioned.