title: Mycoplasma genitalium incidence, organism load, and treatment failure in a cohort of young Australian women.
abstract: BACKGROUND
  Mycoplasma genitalium (MG) is an emerging sexually transmitted infection (STI) that is potentially associated with reproductive tract sequelae in women. This study aimed to estimate MG incidence and treatment failure and provide estimates of organism load in infection.
  
  
  METHODS
  1110 women aged 16-25 years were recruited from primary care clinics in Australia. Women were tested for MG at baseline, 6 months, and 12 months, and MG organism load was measured by quantitative polymerase chain reaction (PCR). MG-positive cases were screened for MG 23S ribosomal RNA (rRNA) gene point mutations shown to confer azithromycin resistance using high-resolution melt following PCR.
  
  
  RESULTS
  MG incidence rate was 1.3 per 100 person-years (n=14; 95% confidence interval [CI], .8-2.3); women reporting 3 or more sex partners in the last 12 months had an increased rate of incident infection (rate ratio [RR], 5.1; 95% CI, 1.3-19.6]). There were 3 cases of MG reinfection (0.8 per 100 person-years [95% CI, .1-.9]. Organism load was higher for prevalent than incident infection (P=.04). There were 3 cases of treatment failure (9.4% [95% CI, 2.0-25.0]); organism load was higher in cases with treatment failure than in successfully treated cases (P<.01). An MG 23S rRNA mutation was detected in 5 cases (3 cases of treatment failure and 2 successfully treated).
  
  
  CONCLUSIONS
  Although MG incidence was relatively low, testing should be recommended for women considered to be at increased risk based on sexual history. Our results also suggest that organism load might be important in azithromycin treatment failure.
authors.affiliation: Centre for Excellence in Rural Sexual Health, Rural Health Academic Centre, Melbourne Medical School, University of Melbourne, Victoria 3010, Australia. walker@unimelb.edu.au
authors.forename: Jennifer
authors.initials: J
authors.lastname: Walker
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Fairley
authors.forename: Catriona S
authors.initials: CS
authors.lastname: Bradshaw
authors.forename: Sepehr N
authors.initials: SN
authors.lastname: Tabrizi
authors.forename: Jimmy
authors.initials: J
authors.lastname: Twin
authors.forename: Marcus Y
authors.initials: MY
authors.lastname: Chen
authors.forename: Nicole
authors.initials: N
authors.lastname: Taylor
authors.forename: Basil
authors.initials: B
authors.lastname: Donovan
authors.forename: John M
authors.initials: JM
authors.lastname: Kaldor
authors.forename: Kathleen
authors.initials: K
authors.lastname: McNamee
authors.forename: Eve
authors.initials: E
authors.lastname: Urban
authors.forename: Sandra
authors.initials: S
authors.lastname: Walker
authors.forename: Marian
authors.initials: M
authors.lastname: Currie
authors.forename: Hudson
authors.initials: H
authors.lastname: Birden
authors.forename: Francis J
authors.initials: FJ
authors.lastname: Bowden
authors.forename: Jane
authors.initials: J
authors.lastname: Gunn
authors.forename: Marie
authors.initials: M
authors.lastname: Pirotta
authors.forename: Lyle
authors.initials: L
authors.lastname: Gurrin
authors.forename: Veerakathy
authors.initials: V
authors.lastname: Harindra
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Garland
authors.forename: Jane S
authors.initials: JS
authors.lastname: Hocking
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001315:Australia / Q000453:epidemiology; D017963:Azithromycin / Q000494:pharmacology / Q000627:therapeutic use*; D058491:Bacterial Load; D015331:Cohort Studies; D021821:Communicable Diseases, Emerging / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D015994:Incidence; D009175:Mycoplasma Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D045704:Mycoplasma genitalium / Q000235:genetics*; D017354:Point Mutation; D012329:RNA, Bacterial / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D015231:Sexually Transmitted Diseases, Bacterial / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D017211:Treatment Failure; D016585:Vaginosis, Bacterial / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D012329:RNA, Bacterial; D012338:RNA, Ribosomal, 23S; D017963:Azithromycin