title: Constant ocular infection with Chlamydia trachomatis predicts risk of scarring in children in Tanzania.
abstract: OBJECTIVE
  Clinically, constant severe trachoma predicts an increased risk of scarring in children. There are no data on the risk of scarring associated with constant infection with Chlamydia trachomatis, regardless of clinical manifestation. We propose to determine the 5-year incidence of scarring in children with a history of constant severe trachoma, constant infection, or both compared with children who had a history of neither.
  
  
  METHODS
  A 5-year, longitudinal observational study.
  
  
  METHODS
  Children aged less than 10 years with data on trachoma and infection for 3 of the 5 visits in the first 18 months, and follow-up 5-year data on scarring.
  
  
  METHODS
  Data were collected on clinical trachoma, and ocular swabs were taken to determine the presence of C. trachomatis in children in a hyperendemic village in Tanzania. Images were graded for scarring. Data were collected at baseline; 2, 6, 12, and 18 months; and 5 years from baseline. Severe trachoma was defined as the presence of 10 or more follicles, or trachoma intense. A child had constant infection (severe trachoma) if infection (severe trachoma) was present on at least 3 visits before the 5-year survey.
  
  
  METHODS
  Five-year risk of scarring.
  
  
  RESULTS
  Of the 189 children, 22 (11.6%) had constant severe trachoma, but not constant infection. Nine children (4.8%) had constant infection but not constant severe trachoma. Both constant severe trachoma and constant infection were present in 16 children (8.5%). The 5-year incidence of scarring was similar in all 3 groups; children with constant severe trachoma only, with constant infection only, and with both were most likely to develop scars (35.0%, 44.4%, 31.2%, respectively) compared with those with sporadic trachoma or infection (15.2%) or neither (6.8%) (P = 0.0002).
  
  
  CONCLUSIONS
  Children with constant infection are also likely to have constant severe trachoma, and their 5-year risk of scarring is high compared with children with sporadic severe trachoma or infection. These data further support the presence of a subgroup of children who cannot clear infection with C. trachomatis, who may manifest a severe immunologic response to infection, and who are at increased risk of scarring sequelae.
  
  
  BACKGROUND
  Proprietary or commercial disclosure may be found after the references.
authors.affiliation: Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
authors.forename: Meraf A
authors.initials: MA
authors.lastname: Wolle
authors.forename: Beatriz E
authors.initials: BE
authors.lastname: Muñoz
authors.forename: Harran
authors.initials: H
authors.lastname: Mkocha
authors.forename: Sheila K
authors.initials: SK
authors.lastname: West
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D017963:Azithromycin / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D002692:Chlamydia trachomatis / Q000302:isolation & purification*; D002921:Cicatrix / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D012307:Risk Factors; D013636:Tanzania / Q000453:epidemiology; D014141:Trachoma / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin