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  • Automated tests for treponemal antibody
  • Large volume laboratories first screen serum with a treponemal test and then retest reactive results with a nontreponemal test--this is called reverse sequence testing
  • Can detect early syphilis and treated syphilis but cannot distinguish them
  • Sometimes identifies persons who are reactive to the treponemal test but nonreactive to the nontreponemal test
  • When results are reactive to both treponemal and RPR tests, persons should be considered to have untreated syphilis unless they have a history of treated syphilis
  • A four fold or greater increase in titer on RPR would indicate a new infection