Loading...
Because of cost and logistics, many labs now screen patients for syphilis with automated treponemal antibody immunoassays and then confirm positive results with the familiar nontreponemal rapid plasma reagin (RPR) or Venereal Disease Research Laboratory tests (JW Gen Med Sep 16 2008). Positive results on both treponemal and nontreponemal testing signify new untreated syphilis. But when the nontreponemal test is negative despite a positive screen, confusion often reigns.
California researchers tabulated clinical data on 255 patients with this serologic pattern, all of whom were subsequently, per current CDC recommendation (MMWR Morb Mortal Wkly Rep 2011; 60:133), retested with a second treponemal screening protocol. A history of syphilis, sta…