title: Risk of Infection with Chlamydia trachomatis from Migrants to Communities Undergoing Mass Drug Administration for Trachoma Control.
abstract: OBJECTIVE
  To determine the risk of infection with Chlamydia trachomatis in children who are migrants to communities who are undergoing mass drug administration (MDA), and if their neighborhoods have higher rates of infection over time.
  
  
  METHODS
  In four communities in Kongwa, Tanzania, all children were enrolled in a longitudinal study of infection and trachoma. New children were identified at census updates as having not been in the community at the previous census. Within communities, neighborhoods were defined as spatially close groups of households, or "balozi". All children in the communities were invited to be examined for trachoma, and have ocular swabs taken for evidence of infection. Trachoma was graded using the World Health Organization simplified grading scheme, and swabs were processed using Amplicor.
  
  
  RESULTS
  Children who were migrants were more likely to be infected and to have trachoma than children who were resident in the community, which was significant by the time of the survey following the third year of MDA (odds ratio, OR, 2.49, 95% confidence interval, CI, 1.03-6.05). The neighborhoods where newcomers resided were more likely to have infection a year later than neighborhoods with no migrants, which was most pronounced following the third year of MDA (OR 2.86, 95% CI 1.07-7.65).
  
  
  CONCLUSIONS
  Migrants to communities may be an important source of re-emergent infection, especially as MDA lowers infection among residents. Highly migrant populations may need a special surveillance and treatment program to avoid slowing progress in communities under MDA.
authors.affiliation: Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, Johns Hopkins University , Baltimore, MD , USA .
authors.forename: Sheila K
authors.initials: SK
authors.lastname: West
authors.forename: Beatriz E
authors.initials: BE
authors.lastname: Munoz
authors.forename: Harran
authors.initials: H
authors.lastname: Mkocha
authors.forename: Charlotte
authors.initials: C
authors.lastname: Gaydos
authors.forename: Thomas
authors.initials: T
authors.lastname: Quinn
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D017963:Azithromycin / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D002692:Chlamydia trachomatis / Q000502:physiology*; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000453:epidemiology*; D019353:Endemic Diseases; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016017:Odds Ratio; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D013636:Tanzania / Q000453:epidemiology; D014141:Trachoma / Q000188:drug therapy / Q000453:epidemiology*; D014171:Transients and Migrants / Q000706:statistics & numerical data*
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin
keywords: Ocular Chlamydia trachomatis; Tanzania; population; prospective study; trachoma