Role of the Venereal Disease Research Laboratory test in the detection of syphilis

Of 9733 consecutive serological samples received by Portsmouth and Southampton Public Health Laboratories (PHL) and tested for syphilis, 190 (140 from men and 50 from women) gave positive results. Thirty new cases of syphilis were identified. Most sera were tested initially by both a specific antibody test (the Treponema pallidum haemaglutination (TPHA) test) and a cardiolipin test (the Venereal Disease Research Laboratory (VDRL) test). Among the 14 patients whose sera gave VDRL-positive but TPHA-negative results, 12 sera gave false-positive results. The sera of 90 patients gave TPHA-positive but VDRL-negative results; sera from only seven of these patients gave false-positive results. The VDRL test is very unlikely to identify a new case of syphilis where a TPHA test has failed to do so. The results of the survey suggest that the VDRL test should be withdrawn from initial testing for syphilis except where early primary disease is suspected.