title: Coinfection with Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis: a cross-sectional analysis of positivity and risk factors in remote Australian Aboriginal communities.
abstract: OBJECTIVE
  To determine the co-occurrence and epidemiological relationships of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) in a high-prevalence setting in Australia.
  
  
  METHODS
  In the context of a cluster randomised trial in 68 remote Aboriginal communities, we obtained laboratory reports on simultaneous testing for CT, NG and TV by nucleic acid amplification tests in individuals aged ≥16 years and examined relationships between age and sex and the coinfection positivity. ORs were used to determine which infections were more likely to co-occur by demographic category.
  
  
  RESULTS
  Of 13 480 patients (median age: 30 years; men: 37%) tested for all three infections during the study period, 33.3% of women and 21.3% of men had at least one of them, highest in patients aged 16-19 years (48.9% in women, 33.4% in men). The most frequent combination was CT/NG (2.0% of women, 4.1% of men), and 1.8% of women and 0.5% of men had all three. In all co-combinations, coinfection positivity was highest in patients aged 16-19 years. CT and NG were highly predictive of each other's presence, and TV was associated with each of the other two infections, but much more so with NG than CT, and its associations were much stronger in women than in men.
  
  
  CONCLUSIONS
  In this remote high-prevalence area, nearly half the patients aged 16-19 years had one or more sexually transmitted infections. CT and NG were more common dual infections. TV was more strongly associated with NG coinfections than with CT. These findings confirm the need for increased simultaneous screening for CT, NG and TV, and enhanced control strategies.
  
  
  BACKGROUND
  Australian and New Zealand Clinical Trials Registry ACTRN12610000358044.
authors.affiliation: The Kirby Institute, University of New South Wales, Sydney, Australia.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Guy
authors.affiliation: Baker IDI Central Australia, Alice Springs, Australia.
authors.forename: James
authors.initials: J
authors.lastname: Ward
authors.affiliation: The Kirby Institute, University of New South Wales, Sydney, Australia.
authors.forename: Handan
authors.initials: H
authors.lastname: Wand
authors.affiliation: Menzies School of Health Research, Darwin, Australia University of Adelaide, Adelaide, Australia.
authors.forename: Alice
authors.initials: A
authors.lastname: Rumbold
authors.affiliation: The Kirby Institute, University of New South Wales, Sydney, Australia NT Department of Health, Sexual Health & Blood Borne Virus Unit, Darwin, Australia.
authors.forename: Linda
authors.initials: L
authors.lastname: Garton
authors.affiliation: Apunipima Cape York Health Council, Cairns, Australia.
authors.forename: Belinda
authors.initials: B
authors.lastname: Hengel
authors.affiliation: Menzies School of Health Research, Darwin, Australia.
authors.forename: Bronwyn
authors.initials: B
authors.lastname: Silver
authors.affiliation: Menzies School of Health Research, Darwin, Australia.
authors.forename: Debbie
authors.initials: D
authors.lastname: Taylor-Thomson
authors.affiliation: Lismore sexual health service, NSW health, Sydney, Australia.
authors.forename: Janet
authors.initials: J
authors.lastname: Knox
authors.affiliation: The Kirby Institute, University of New South Wales, Sydney, Australia.
authors.forename: Skye
authors.initials: S
authors.lastname: McGregor
authors.affiliation: The Kirby Institute, University of New South Wales, Sydney, Australia.
authors.forename: Amalie
authors.initials: A
authors.lastname: Dyda
authors.affiliation: Melbourne Sexual Health Centre, Carlton, Australia Monash University, Melbourne, Australia.
authors.forename: Christopher
authors.initials: C
authors.lastname: Fairley
authors.affiliation: The Kirby Institute, University of New South Wales, Sydney, Australia.
authors.forename: Lisa
authors.initials: L
authors.lastname: Maher
authors.affiliation: The Kirby Institute, University of New South Wales, Sydney, Australia Sydney Sexual Health Centre, Sydney Hospital, Sydney, Australia.
authors.forename: Basil
authors.initials: B
authors.lastname: Donovan
authors.affiliation: The Kirby Institute, University of New South Wales, Sydney, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Kaldor
mesh_terms: D000293:Adolescent; D000328:Adult; D001315:Australia / Q000453:epidemiology; D002690:Chlamydia Infections / Q000150:complications* / Q000453:epidemiology*; D002692:Chlamydia trachomatis / Q000302:isolation & purification; D060085:Coinfection / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005260:Female; D006069:Gonorrhea / Q000150:complications* / Q000453:epidemiology*; D006801:Humans; D008297:Male; D009344:Neisseria gonorrhoeae / Q000302:isolation & purification; D021141:Nucleic Acid Amplification Techniques; D012307:Risk Factors; D014245:Trichomonas Infections / Q000150:complications* / Q000453:epidemiology*; D014246:Trichomonas vaginalis / Q000302:isolation & purification; D055815:Young Adult
keywords: EPIDEMIOLOGY (GENERAL); INFECTIOUS DISEASES; SCREENING