title: Quantitative microhaemagglutination assay for Treponema pallidum antibodies in experimental syphilis.
abstract: The quantitative microhaemagglutination assay for Treponema pallidum antibodies (MHA-TP) was studies in 52 untreated and treated rabbits with experimental syphilis. Rabbits with incubating experimental syphilis were cured or inadequately treated with penicillin G and some cured rabbits were later reinfected. MHA-TP conversion occurred within 45 days in untreated rabbits. Titres reached peak levels about four months after inoculation and remained relatively high for up to two years. The quantitative MHA-TP test differentiated between rabbits cured of experimental incubating syphilis and those untreated and inadequately treated. MHA-TP titres decreased after treatment given six or 12 months after inoculation but reversion did not occur. MHA-TP conversion or significant increases in titre occurred as soon as seven days after reinfection and preceded corresponding changes in a quantitative non-treponemal test. The MHA-TP is useful as a screening test for treponemal antibodies in rabbits. The quantitative MHA-TP in humans after treatment for syphilis and reinfection deserves further study.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D006386:Hemagglutination Tests / Q000379:methods; D008297:Male; D010401:Penicillin G Benzathine / Q000627:therapeutic use; D011817:Rabbits; D013587:Syphilis / Q000188:drug therapy / Q000276:immunology; D013588:Syphilis Serodiagnosis / Q000379:methods*; D013997:Time Factors; D014210:Treponema pallidum / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D010401:Penicillin G Benzathine