A Comparative Study of the VDRL and FTA-ABS Tests in Korea

ABSTRACT

During the period from January to December 1976, 12,489 VDRL (Venereal Disease Research Laboratory) and 2,965 FTA-ABS (Fluorescent Treponemal Antibody Absorption) tests were made. The reactive VDRL tests represented 3.6% of the total tested and the reactive rate of the FTA-ABS was 17.4%. The reactive VDRL and FTA-ABS tests represented 422 patients with clinically known diseases. The purpose of this study was to correlate the serologic findings with clinical problems. We divided the patients into three groups: 1. those with clinically diagnosed syphilis, 2. those with a history or physical findings compatible with syphilis, 3. those with no clinical evidence of syphilis. In groups 1 and 2, which represented 27% and 36.7%, respectively, a close correlation occurred between the two tests, both being reactive in 93-98% of the patients. However the VDRL was more informative than the FTA-ABS in determining clinical stages. In group 3, representing 36.3% of the reactive tests, the agreement between the two tests dropped to 77%; the FTA-ABS test was reactive in an additional 32 cases, 21% more than the VDRL. These discrepancies may well be due to the greater sensitivity of the FTA-ABS test in very early or late syphilis when there are no clinically recognizable manifestations. However the possibility of false positive FTA-ABS reactions could not be ruled out.