title: Repeated Chlamydia trachomatis genital infections in adolescent women.
abstract: BACKGROUND
  Repeated Chlamydia trachomatis infections are common among young sexually active women. The relative frequency of reinfection and antibiotic treatment failure is undefined.
  
  
  METHODS
  Adolescent women enrolled in a longitudinal cohort had behavioral and sexually transmitted infection assessments performed every 3 months, including amplification tests for C. trachomatis, ompA genotyping, and interviews and diary entries to document sex partner-specific coitus and event-specific condom use. Repeated infections were classified as reinfection or treatment failure by use of an algorithm. All infections for which treatment outcomes were known were used to estimate the effectiveness of antibiotic use.
  
  
  RESULTS
  We observed 478 episodes of infection among 210 study participants; 176 women remained uninfected. The incidence rate was 34 episodes/100 woman-years. Of the women who were infected, 121 experienced 1 repeated infections, forming 268 episode pairs; 183 pairs had complete data available and were classified using the algorithm. Of the repeated infections, 84.2% were definite, probable, or possible reinfections; 13.7% were probable or possible treatment failures; and 2.2% persisted without documented treatment. For 318 evaluable infections, we estimated 92.2% effectiveness of antibiotic use.
  
  
  CONCLUSIONS
  Most repeated chlamydial infections in this high-incidence cohort were reinfections, but repeated infections resulting from treatment failures occurred as well. Our results have implications for male screening and partner notification programs and suggest the need for improved antibiotic therapies.
authors.affiliation: Divisions of Infectious Diseases, Indiana University School of Medicine, Indianapolis, Indiana 46202-5112, USA. bbatteig@iupui.edu
authors.forename: Byron E
authors.initials: BE
authors.lastname: Batteiger
authors.forename: Wanzhu
authors.initials: W
authors.lastname: Tu
authors.forename: Susan
authors.initials: S
authors.lastname: Ofner
authors.forename: Barbara
authors.initials: B
authors.lastname: Van Der Pol
authors.forename: Diane R
authors.initials: DR
authors.lastname: Stothard
authors.forename: Donald P
authors.initials: DP
authors.lastname: Orr
authors.forename: Barry P
authors.initials: BP
authors.lastname: Katz
authors.forename: J Dennis
authors.initials: JD
authors.lastname: Fortenberry
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D017963:Azithromycin / Q000627:therapeutic use*; D015373:Bacterial Typing Techniques; D002690:Chlamydia Infections / Q000188:drug therapy* / Q000453:epidemiology*; D002692:Chlamydia trachomatis / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D007196:Indiana / Q000453:epidemiology; D008137:Longitudinal Studies; D055118:Medication Adherence; D015995:Prevalence; D012725:Sexual Behavior
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin