title: Alterations in the conjunctival bacterial flora following a single dose of azithromycin in a trachoma endemic area.
abstract: OBJECTIVE
  The World Health Organisation has recommended repeated mass treatment of children in trachoma endemic areas with oral azithromycin. While chlamydia, the causative agent of trachoma, remains universally sensitive to azithromycin, there is concern that large scale programmes may alter the bacterial flora and induce resistance in streptococcal species. In this study the effect of a single dose of azithromcyin on the prevalence, species distribution, and resistance of conjunctival bacterial flora was determined.
  
  
  METHODS
  Baseline and 14 day follow up bacterial cultures were taken from the conjunctivae of 121 children who reside in a trachoma endemic area of Nepal. 91 children were treated with azithromycin at baseline and 31 children received deferred treatment at the 14 day follow up.
  
  
  RESULTS
  Although the prevalence of bacterial pathogens decreased significantly with azithromycin treatment, a significant change in the distribution of specific bacterial pathogens could not be demonstrated. Streptococcal resistance to azithromycin was found significantly more frequently after treatment. No change in the prevalence, distribution, or resistance pattern was found in the untreated control group.
  
  
  CONCLUSIONS
  Repeated mass treatment of trachoma endemic areas with oral azithromycin will have an effect on bacterial flora. However, further work needs to be done to determine if this will have any clinical relevance.
authors.affiliation: Francis I Proctor Foundation and the Department of Ophthalmology, University of California, San Francisco, CA, USA.
authors.forename: K C
authors.initials: KC
authors.lastname: Chern
authors.forename: S K
authors.initials: SK
authors.lastname: Shrestha
authors.forename: V
authors.initials: V
authors.lastname: Cevallos
authors.forename: H L
authors.initials: HL
authors.lastname: Dhami
authors.forename: P
authors.initials: P
authors.lastname: Tiwari
authors.forename: L
authors.initials: L
authors.lastname: Chern
authors.forename: J P
authors.initials: JP
authors.lastname: Whitcher
authors.forename: T M
authors.initials: TM
authors.lastname: Lietman
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017963:Azithromycin / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D003228:Conjunctiva / Q000382:microbiology*; D019353:Endemic Diseases; D006801:Humans; D007223:Infant; D008826:Microbial Sensitivity Tests; D009390:Nepal / Q000453:epidemiology; D013296:Streptococcus pneumoniae / Q000187:drug effects; D014141:Trachoma / Q000188:drug therapy* / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin