Trends in seroreactivity for syphilis among pregnant Nigerian women.

Results These are presented in table 1. Owing to the unavailability of the Treponema pallidum haemagglutination assay (TPHA) reagents at certain times and the inability of some women to aVord the cost of screening, only 30 of the 148 VDRL reactive serum samples were subjected to TPHA, with three being positive. Thus, 10% of the VDRL reactive sera were also TPHA reactive. This TPHA/VDRL ratio is similar to the 11.6% observed in an earlier study in our centre. Should this ratio be projected for other VDRL reactive sera not subjected to the TPHA test, a total of 15 TPHA reactive sera may be obtained. This will give a VDRL and TPHA reactivity of 0.13%.