title: Treatment efficacy of azithromycin 1 g single dose versus doxycycline 100 mg twice daily for 7 days for the treatment of rectal chlamydia among men who have sex with men - a double-blind randomised controlled trial protocol.
abstract: Rectal infection with Chlamydia trachomatis is one of the most common bacterial sexually transmissible infections among men who have sex with men (MSM) with diagnosis rates continuing to rise. Current treatment guidelines recommend either azithromycin 1 g single dose or doxycycline 100 mg twice daily for 7 days. However, there are increasing concerns about treatment failure with azithromycin. We are conducting the first randomised controlled trial (RCT) to compare treatment efficacy of azithromycin versus doxycycline for the treatment of rectal chlamydia in MSM.
  
  
  
  The Rectal Treatment Study will recruit 700 MSM attending Australian sexual health clinics for the treatment of rectal chlamydia. Participants will be asked to provide rectal swabs and will be randomised to either azithromycin 1 g single dose or doxycycline 100 mg twice daily for 7 days. Participants will be asked to complete questionnaires about adverse drug reactions, sexual behaviour and drug adherence via short message service and online survey. The primary outcome is the treatment efficacy as determined by a negative chlamydia nucleic acid amplification test at 4 weeks post treatment. Secondary outcomes will utilise whole genome sequencing and mRNA assay to differentiate between treatment failure, reinfection or false positive results.
  
  
  
  Rectal chlamydia is an increasing public health concern as use of pre-exposure prophylaxis against HIV becomes commonplace. Optimal, evidence-based treatment is critical to halting ongoing transmission. This study will provide the first RCT evidence comparing azithromycin and doxycycline for the treatment of rectal chlamydia. The results of this trial will establish which treatment is more efficacious and inform international management guidelines.
  
  
  
  Australian New Zealand Clinical Trials Registry ACTRN12614001125617.
authors.affiliation: Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Carlton, 3053, VIC, Australia.
authors.forename: Andrew
authors.identifier: 0000-0002-5240-8468
authors.initials: A
authors.lastname: Lau
authors.affiliation: Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Carlton, 3053, VIC, Australia.
authors.forename: Fabian
authors.initials: F
authors.lastname: Kong
authors.affiliation: Melbourne Sexual Health Centre, Alfred Health, 580 Swanston St, Carlton, 3053, VIC, Australia.|Central Clinical School, Monash University, Clayton, 3800, VIC, Australia.
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Fairley
authors.affiliation: The Kirby Institute, UNSW Australia, Kensington, 2052, NSW, Australia.
authors.forename: Basil
authors.initials: B
authors.lastname: Donovan
authors.affiliation: Melbourne Sexual Health Centre, Alfred Health, 580 Swanston St, Carlton, 3053, VIC, Australia.|Central Clinical School, Monash University, Clayton, 3800, VIC, Australia.
authors.forename: Marcus
authors.initials: M
authors.lastname: Chen
authors.affiliation: Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Carlton, 3053, VIC, Australia.|Melbourne Sexual Health Centre, Alfred Health, 580 Swanston St, Carlton, 3053, VIC, Australia.|Central Clinical School, Monash University, Clayton, 3800, VIC, Australia.
authors.forename: Catriona
authors.initials: C
authors.lastname: Bradshaw
authors.affiliation: The Kirby Institute, UNSW Australia, Kensington, 2052, NSW, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Boyd
authors.affiliation: The Kirby Institute, UNSW Australia, Kensington, 2052, NSW, Australia.
authors.forename: Janaki
authors.initials: J
authors.lastname: Amin
authors.affiliation: University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, 4556, QLD, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Timms
authors.affiliation: Division of Laboratory Services, Department of Microbiology, University of Melbourne, Carlton, 3053, VIC, Australia.
authors.forename: Sepehr
authors.initials: S
authors.lastname: Tabrizi
authors.affiliation: The Kirby Institute, UNSW Australia, Kensington, 2052, NSW, Australia.
authors.forename: David G
authors.initials: DG
authors.lastname: Regan
authors.affiliation: Western Sydney Sexual Health Centre, 162 Marsden St, Parramatta, 2150, NSW, Australia.|Marie Bashir Institute for Infectious Diseases and Biosecurity & Sydney Medical School-Westmead, University of Sydney, Sydney, 2000, NSW, Australia.
authors.forename: David A
authors.initials: DA
authors.lastname: Lewis
authors.affiliation: Sydney Sexual Health Centre, Level 3 Nightingale Wing, Sydney Hospital, Macquarie St, Sydney, 2000, NSW, Australia.
authors.forename: Anna
authors.initials: A
authors.lastname: McNulty
authors.affiliation: Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Carlton, 3053, VIC, Australia. j.hocking@unimelb.edu.au.|Melbourne Sexual Health Centre, Alfred Health, 580 Swanston St, Carlton, 3053, VIC, Australia. j.hocking@unimelb.edu.au.
authors.forename: Jane S
authors.initials: JS
authors.lastname: Hocking
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D001315:Australia; D017963:Azithromycin / Q000008:administration & dosage* / Q000627:therapeutic use; D002690:Chlamydia Infections / Q000188:drug therapy*; D002692:Chlamydia trachomatis / Q000235:genetics / Q000472:pathogenicity; D002985:Clinical Protocols; D004311:Double-Blind Method; D004318:Doxycycline / Q000008:administration & dosage* / Q000627:therapeutic use; D004334:Drug Administration Schedule; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D021141:Nucleic Acid Amplification Techniques; D016032:Randomized Controlled Trials as Topic; D012002:Rectal Diseases / Q000188:drug therapy* / Q000382:microbiology; D011795:Surveys and Questionnaires; D017211:Treatment Failure; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin; D004318:Doxycycline
keywords: Chlamydia; MSM; azithromycin; doxycycline; rectal; treatment