title: Mass treatment with single-dose azithromycin for trachoma.
abstract: BACKGROUND
  Trachoma, caused by repeated ocular infection with Chlamydia trachomatis, is an important cause of blindness. Current recommended dosing intervals for mass azithromycin treatment for trachoma are based on a mathematical model.
  
  
  METHODS
  We collected conjunctival swabs for quantitative polymerase-chain-reaction assay of C. trachomatis before and 2, 6, 12, 18, and 24 months after mass treatment with azithromycin in a Tanzanian community in which trachoma was endemic. For ethical reasons, at 6, 12, and 18 months, we gave tetracycline eye ointment to residents who had clinically active trachoma.
  
  
  RESULTS
  At baseline, 956 of 978 residents (97.8 percent) received either one oral dose of azithromycin or (if azithromycin was contraindicated) a course of tetracycline eye ointment. The prevalence of infection fell from 9.5 percent before mass treatment to 2.1 percent at 2 months and 0.1 percent at 24 months. The quantitative burden of ocular C. trachomatis infection in the community was 13.9 percent of the pretreatment level at 2 months and 0.8 percent at 24 months. At each time point after baseline, over 90 percent of the total community burden of C. trachomatis infection was found among subjects who had been positive the previous time they were tested.
  
  
  CONCLUSIONS
  The prevalence and intensity of infection fell dramatically and remained low for two years after treatment. One round of very-high-coverage mass treatment with azithromycin, perhaps aided by subsequent periodic use of tetracycline eye ointment for persons with active disease, can interrupt the transmission of ocular C. trachomatis infection.
authors.affiliation: Clinical Research Unit, London School of Hygiene and Tropical Medicine, London, United Kingdom. anthony.solomon@lshtm.ac.uk
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Solomon
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Holland
authors.forename: Neal D E
authors.initials: ND
authors.lastname: Alexander
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Massae
authors.forename: Aura
authors.initials: A
authors.lastname: Aguirre
authors.forename: Angels
authors.initials: A
authors.lastname: Natividad-Sancho
authors.forename: Sandra
authors.initials: S
authors.lastname: Molina
authors.forename: Salesia
authors.initials: S
authors.lastname: Safari
authors.forename: John F
authors.initials: JF
authors.lastname: Shao
authors.forename: Paul
authors.initials: P
authors.lastname: Courtright
authors.forename: Rosanna W
authors.initials: RW
authors.lastname: Peeling
authors.forename: Sheila K
authors.initials: SK
authors.lastname: West
authors.forename: Robin L
authors.initials: RL
authors.lastname: Bailey
authors.forename: Allen
authors.initials: A
authors.lastname: Foster
authors.forename: David C W
authors.initials: DC
authors.lastname: Mabey
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D019072:Antibiotic Prophylaxis; D017963:Azithromycin / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D002692:Chlamydia trachomatis / Q000302:isolation & purification; D003228:Conjunctiva / Q000382:microbiology; D004334:Drug Administration Schedule; D019353:Endemic Diseases; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D009824:Ointments; D011247:Pregnancy; D015995:Prevalence; D013636:Tanzania / Q000453:epidemiology; D013752:Tetracycline / Q000008:administration & dosage; D014141:Trachoma / Q000188:drug therapy* / Q000453:epidemiology / Q000635:transmission
chemical_list: D000900:Anti-Bacterial Agents; D009824:Ointments; D017963:Azithromycin; D013752:Tetracycline