text: An indirect agglutination assay used to detect this disease first sensitizes gelatin particles to antigens of this disease before checking for gelatin clumping.
full_question: An indirect agglutination assay used to detect this disease first sensitizes gelatin particles to antigens of this disease before checking for gelatin clumping. Lyophilized suspensions of this disease's causative agent are mixed with the patient's serum in another test for this disease. Screening methods for this disease such as VDRL are followed by TPPA and FTP-ABS tests for it. Painless lesions called chancres often accompany the early stages of this disease, while many patients with its late-stage form go insane. For 10 points, name this sexually transmitted disease that is caused by Treponema pallidum.
first_sentence: An indirect agglutination assay used to detect this disease first sensitizes gelatin particles to antigens of this disease before checking for gelatin clumping.