title: Behavioural sources of repeat Chlamydia trachomatis infections: importance of different sex partners.
abstract: OBJECTIVE
  To examine sources of repeat Chlamydia trachomatis infections using behavioural and molecular methods.
  
  
  METHODS
  Women with C. trachomatis had baseline and 4-month follow-up visits consisting of behavioural surveys and genotyping of C. trachomatis. Frequencies and population-attributable risk percentages (PAR%) were estimated for possible sources of repeat infections including sex partners not known to be treated, new sex partners, and sex partners not known to be monogamous. Women with different genotypes at baseline and follow-up were classified as different partner sources of infection.
  
  
  RESULTS
  The cumulative incidence of repeat infections in the sample (n=183) was 13% (95% CI 8% to 18%). Predictors of repeat infections included younger age and continued sex with a partner not known to be treated. Frequencies of having partners not known to be treated, new partners, or partners not known to be monogamous at follow-up were 21% (95% CI 15% to 27%), 37% (95% CI 30% to 44%) and 33% (95% CI 28% to 41%), respectively. The PAR% for having a partner not known to be treated was 26% (95% CI 3% to 49%) and for having a new sex partner was 21% (95% CI 0% to 50%). Among eight patients with available genotypes at baseline and follow-up, five had different genotypes and were classified as having a different partner source of infection.
  
  
  CONCLUSIONS
  Different sex partner sources of repeat C. trachomatis infections other than untreated sex partners may contribute substantially to the burden of repeat infections.
authors.affiliation: Yale School of Public Health, 60 College Street, New Haven, CT 06520, USA. linda.niccolai@yale.edu
authors.forename: Linda M
authors.initials: LM
authors.lastname: Niccolai
authors.forename: Kara A
authors.initials: KA
authors.lastname: Livingston
authors.forename: Alison S
authors.initials: AS
authors.lastname: Laufer
authors.forename: Melinda M
authors.initials: MM
authors.lastname: Pettigrew
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D017963:Azithromycin / Q000627:therapeutic use; D002690:Chlamydia Infections / Q000453:epidemiology / Q000635:transmission*; D002692:Chlamydia trachomatis; D003075:Coitus; D017280:Condoms / Q000706:statistics & numerical data; D017281:Cost of Illness; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012725:Sexual Behavior; D012747:Sexual Partners; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin