title: Relapse of secondary syphilis after benzathine penicillin G: molecular analysis.
abstract: OBJECTIVE
  It is difficult to distinguish between relapse and reinfection in patients who develop a second episode of syphilis after treatment.
  
  
  OBJECTIVE
  The goal of this study was to use molecular methods to distinguish between relapse and reinfection in a patient with recurrent secondary syphilis.
  
  
  METHODS
  Treponema pallidum tprK sequences were amplified from cerebrospinal fluid (CSF), skin, and blood from the initial presentation and from blood from the second presentation. Neighbor-joining clustering analysis was performed for deduced tprK sequences from the case patient and for sequences derived from blood and CSF of a different patient with secondary syphilis.
  
  
  RESULTS
  The case patient's tprK sequences from both episodes of syphilis clustered together with a high degree of similarity.
  
  
  CONCLUSIONS
  Our patient likely relapsed despite treatment.
authors.affiliation: Department of Medicine (Infectious Diseases), University of Washington School of Medicine, Seattle, Washington, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Myint
authors.forename: Houman
authors.initials: H
authors.lastname: Bashiri
authors.forename: Robert D
authors.initials: RD
authors.lastname: Harrington
authors.forename: Christina M
authors.initials: CM
authors.lastname: Marra
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001426:Bacterial Proteins; D015658:HIV Infections / Q000150:complications; D006801:Humans; D008297:Male; D010401:Penicillin G Benzathine / Q000627:therapeutic use*; D018272:Porins / Q000235:genetics; D012008:Recurrence; D012703:Serotyping; D013587:Syphilis / Q000134:cerebrospinal fluid / Q000150:complications / Q000188:drug therapy*; D017211:Treatment Failure; D014210:Treponema pallidum / Q000145:classification
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D018272:Porins; C099361:major outer sheath protein, Treponema; D010401:Penicillin G Benzathine