Recent observations on the serology of syphilis.

Abstract

Routine screening of 404,742 sera by the automated micro-hemagglutination assay (AMHA-TP) and the Venereal Disease Research Laboratory (VDRL) test showed that 9848 specimens gave a reactive result to 1 of the 3 assays. Reactive results were confirmed by the fluorescent treponemal antibody absorption (FTA-ABS) test. The possibility of false-positive results varied from 0.04-0.38% of all specimens or from 1.7-15.7% of reactive sera. The VDRL test failed to detect reactivity in 56.54% of sera from patients who previously were infected with Treponema pallidum. The importance of routine testing by the AMHA-TP is illustrated by the detection of 4 patients with mesaortitis and 2 with active neurosyphilis among a selected group of 54 patients who had non-reactive results to the VDRL test. Testing of CSF specimens by the AMHA-TP test produced more specific results than by the other 2 tests.