Seroprevalence of syphilis by TPHA test

A total of 1074 sera obtained from clinically suspected cases of Syphilis and various risk groups were screened for antitreponemal antibodies by Treponema pallidum Haemagglutination (TPHA) test and cardiolipin antibodies by the Venereal Disease Research Laboratory (VDRL) tests. The TPHA test was positive in 291 (27.09) per cent. The TPHA was positive in 53.31 per cent (161 out of 302) patients of primary syphilis, 54.17 per cent (26 out of 48) of secondary, 32.76 per cent (19 out of 58) of tertiary syphilis, 17.12 per cent (19 out of 111) of other Sexually Transmitted Disease (STD) patients, 25.32 per cent (60 out of 237) pregnant women and 1.89 per cent (6 out of 318) healthy individuals. TPHA was found to be superior to VDRL test in all the study groups. Almost a total agreement was seen between the TPHA test and VDRL test with a titre of 1 in 16 & above; while in as many as 32.39 per cent sera with VDRL titre of 1 in 8 TPHA was negative indicating that the VDRL titres above 1 in 8 should be considered as true reactives to minimize the biological false positive reactions.