High-titer positive nontreponemal tests with negative specific treponemal serology in patients with HIV infection and/or intravenous substance use.

Nontreponemal testing is a valuable tool in screening for syphilis. False-positive reactions are uncommon and are usually at a titer less than 1:8. We describe eight intravenous substance abusers and/or HIV-positive patients with high-titer (greater than or equal to 1:16) nontreponemal and negative treponemal serologies in whom the diagnosis of syphilis is unproven and possibly false.