Reverse Sequence Syphilis Screening and Discordant Results in Pregnancy.

A "reverse sequence syphilis screening" algorithm is widely used for syphilis testing. This retrospective study showed that most (65%) pregnant women with discordant screening results (treponemal multiplex flow immunoassay IgG+/rapid plasma reagin-) had a nonreactive confirmatory Treponema pallidum-particle agglutination assay, likely indicative of a false-positive reaction.