Abstract

Sera from 225 patients who 20 years earlier had been infected with endemic syphilis and adequately treated with penicillin (PAM 4.8-6 megaunits) at various stages of the disease, were investigated for serological reactivity by the fluorescent treponemal antibody absorption (FTA-ABS), treponemal haemagglutination, and Venereal Diseases Research Laboratory tests. Specific antibodies were found in a large percentage of cases and their presence may be assumed to depend on persisting specific antigen which stimulates their synthesis.