Chlamydia trachomatis test-of-cure cannot be based on a single highly sensitive laboratory test taken at least 3 weeks after treatment

PLoS One. 2012;7(3):e34108. doi: 10.1371/journal.pone.0034108. Epub 2012 Mar 28.


Current test-of-cure practice in patients with Chlamydia trachomatis (Ct) infection is to confirm cure with a single test taken at least 3 weeks after treatment. Effectiveness of single-time-point testing however lacks a scientific evidence basis and the high sensitivity of laboratory assays nowadays in use for this purpose may compromise the clinical significance of their results. Prospectively following 59 treated Ct infections, administering care as usual, the presence of Ct plasmid DNA and rRNA was systematically assessed by multiple time-sequential measurements, i.e. on 18 samples taken per patient during 8 weeks following treatment with a single dose of 1000 mg Azythromycin. A high proportion (42%) of Ct infections tested positive on at least one of the samples taken after 3 weeks. Patients' test results showed substantial inter-individual and intra-individual variation over time and by type of NAAT used. We demonstrated frequent intermittent positive patterns in Ct test results over time, and strongly argue against current test-of-cure practice.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / therapeutic use*
  • Azithromycin / therapeutic use*
  • Chlamydia Infections / diagnosis*
  • Chlamydia Infections / drug therapy*
  • Chlamydia Infections / microbiology
  • Chlamydia trachomatis / genetics*
  • Chlamydia trachomatis / isolation & purification
  • DNA, Bacterial / analysis
  • Female
  • Humans
  • Male
  • RNA, Ribosomal / analysis
  • Time Factors


  • Anti-Bacterial Agents
  • DNA, Bacterial
  • RNA, Ribosomal
  • Azithromycin