title: Chlamydia trachomatis genotypes among men who have sex with men in Australia.
abstract: BACKGROUND
  Chlamydia trachomatis is a common bacterial sexually transmitted infection in men who have sex with men (MSM), although little is known about its distribution in Australian MSM communities.
  
  
  METHODS
  From 2004 to 2008, 612 consecutive C. trachomatis positive anal swab and urine samples were collected for genotyping and quantification from MSM attending 2 sexual health centers (Melbourne and Sydney).
  
  
  RESULTS
  The most common serovars detected were D (35.2%), G (32.7%), and J (17.7%), although these distributions changed significantly by year and city. C. trachomatis infections (2.8%) involved more than 1 serovar and only 1 lymphogranuloma venereum isolate was detected. The majority of serovar strains showed an identical omp1 genotype, with only 7.5% showing genotypic variability. Serovar G infections were not associated with overseas sexual activity; whilst individuals with serovar J were less likely to have had a prior C. trachomatis infection, and with serovar E were those who had prior C. trachomatis infection. Symptoms were present in 68% of urethral infections and 28% anal infections, and were associated with gonorrheal coinfection (13.8%), prior C. trachomatis infection (20.6%) and increasing age. A higher C. trachomatis load was identified in anal samples versus urine (1.48 × 10(4) genome copies/anal swab; 3.72 × 10(3) copies/mL urine) and no association was made to concentration including the presence of symptoms and prior C. trachomatis infection.
  
  
  CONCLUSIONS
  This is the largest study of C. trachomatis serovars in MSM: it is the first to report C. trachomatis rectal loads, and provides an overview on C. trachomatis serovars and genotypic variants that circulate in Australian MSM communities.
authors.affiliation: Department of Microbiology and Infectious Diseases, The Royal Women's Hospital, Melbourne, Australia. jimmy.twin@mcri.edu.au
authors.forename: Jimmy
authors.initials: J
authors.lastname: Twin
authors.forename: Elya E
authors.initials: EE
authors.lastname: Moore
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Garland
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Stevens
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Fairley
authors.forename: Basil
authors.initials: B
authors.lastname: Donovan
authors.forename: William
authors.initials: W
authors.lastname: Rawlinson
authors.forename: Sepehr N
authors.initials: SN
authors.lastname: Tabrizi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001003:Anal Canal / Q000382:microbiology; D001004:Anus Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D002690:Chlamydia Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D002692:Chlamydia trachomatis / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D015331:Cohort Studies; D060085:Coinfection / Q000382:microbiology; D005838:Genotype; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D008875:Middle Aged; D009517:New South Wales / Q000453:epidemiology; D015995:Prevalence; D012703:Serotyping; D012725:Sexual Behavior; D012747:Sexual Partners; D014521:Urethra / Q000382:microbiology; D014522:Urethral Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D014739:Victoria / Q000453:epidemiology; D055815:Young Adult