A total of 19,067 sera were screened for biological false positive (BFP) reactivity by the Venereal Disease Research Laboratory (VDRL) test. Sera which were reactive in the VDRL test were confirmed by the fluorescent treponemal antibody absorption (FTA-ABS) test. BFP reactions were detected in 0.59% of the general population, 0.72% of pregnant women and 11.8% of patients with systemic lupus erythematosus (SLE). The rate of BFP reactors among pregnant women did not differ significantly from the general population. The female to male ratio of BFP in the general population was 2:1 whilst that in the group of patients with SLE was 8:1. The overall seroprevalence of syphilis was 2.2%.
PIP: The Venereal Disease Research Laboratory (VDRL) test for syphilis was used to screen 19,067 Jamaican sera, and positive were confirmed with the fluorescent Treponema pallidum haemagglutination assay (FTA-ABS). The group included 15,876 persons applying for emigration, 3039 pregnant women attending prenatal care, and 152 patients with systemic lupus erythematosus (SLE). 2.8% of the general population were VDRL positive, and of these 21.3% had titers 1:4. 4.7% of the pregnant women were positive, 48.2% with titers 1:4. 27.1% of the VDRL positive in the general population and 30.9% of the pregnant women were false positive, i.e.negative on the FTA-ABS test. 78.2% of the SLE patients were false positive on the VDRL, including 1 patient with a titer of 1:128. Thus the percentage of false positive taking the whole group as denominator was 0.59% in the general population, 0.72% in the pregnant women, but 11.8% among SLE patients. The overall seroprevalence of syphilis was 2.2%. These results are atypical in that pregnant women are usually considered to have a high rate of false positive results on the VDRL.