title: Mass distribution of azithromycin for trachoma control is associated with increased risk of azithromycin-resistant Streptococcus pneumoniae carriage in young children 6 months after treatment.
abstract: BACKGROUND
  Emerging evidence suggests that the mass distribution of azithromycin for trachoma control (MDA) may increase circulation of macrolide resistance in bacteria associated with severe pediatric infections in treated communities.
  
  
  METHODS
  We examined the effect of MDA on nasopharyngeal carriage of antibiotic-resistant Streptococcus pneumoniae among 1015 young children living in rural Tanzania. MDA with a single dose of oral azithromycin was provided in 4 of 8 communities where trachoma prevalence was ≥10%. Isolates were tested for susceptibility to azithromycin (AZM) and commonly used antibiotics by disk diffusion and Etest. We calculated the proportion of antibiotic-resistant S. pneumoniae carriage at baseline and again 1, 3, and 6 months after treatment, and at comparable intervals in the untreated villages.
  
  
  RESULTS
  The proportion of AZM-resistant isolates was similar between groups at baseline (MDA: 35.8% vs non-MDA: 35.4%), however, this proportion was greater in the MDA group in all subsequent surveys. At 6 months, the percentage of AZM-resistant isolates was significantly higher in the MDA group (81.9% vs 46.9%, P < .001). The odds of AZM-resistant carriage was 5-fold greater in the MDA group (odds ratio, 4.95 [95% confidence interval, 3.23-7.61]). The proportion of isolates clinically resistant to AZM (minimum inhibitory concentration ≥16 µg/mL) was also significantly greater in the MDA group at 6 months (35.3% vs 12.4%, P < .006).
  
  
  CONCLUSIONS
  Mass distribution of a single dose of oral azithromycin for trachoma was associated with increased circulation of macrolide-resistant S. pneumoniae carriage among young children in the 6 months following treatment. It is crucial that changes in antibiotic resistance patterns and their clinical significance in the treatment of severe pediatric infections be assessed in future MDA trials.
authors.affiliation: Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, 615 N Wolfe St, Rm W5009, Baltimore, MD 21205, USA. ccoles@jhsph.edu
authors.forename: Christian L
authors.initials: CL
authors.lastname: Coles
authors.forename: Kasubi
authors.initials: K
authors.lastname: Mabula
authors.forename: Jessica C
authors.initials: JC
authors.lastname: Seidman
authors.forename: Joshua
authors.initials: J
authors.lastname: Levens
authors.forename: Harran
authors.initials: H
authors.lastname: Mkocha
authors.forename: Beatriz
authors.initials: B
authors.lastname: Munoz
authors.forename: Sayoki G
authors.initials: SG
authors.lastname: Mfinanga
authors.forename: Sheila
authors.initials: S
authors.lastname: West
mesh_terms: D000284:Administration, Oral; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000009:adverse effects; D017963:Azithromycin / Q000008:administration & dosage* / Q000009:adverse effects; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology*; D002675:Child, Preschool; D015331:Cohort Studies; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D015995:Prevalence; D012307:Risk Factors; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000302:isolation & purification; D013636:Tanzania / Q000453:epidemiology; D014141:Trachoma / Q000188:drug therapy* / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin
keywords: S. pneumoniae; antimicrobial resistance; azithromycin; children; trachoma