title: Trachoma among children in community surveys from four African countries and implications of using school surveys for evaluating prevalence.
abstract: BACKGROUND
  School surveys provide a convenient platform to obtain large child cohorts from multiple communities and are widely used as a proxy to determine community prevalence of neglected tropical diseases. The purpose of this study was to compare trachoma prevalence between preschool- and school-aged children and children who attend and do not attend school.
  
  
  METHODS
  We analysed data from community-based trachoma surveys conducted from 2008-2011 in Ethiopia, Mali, Niger and Nigeria. The surveys utilised a cross-sectional, randomised cluster design. Individual-level data on school attendance was collected.
  
  
  RESULTS
  Overall, 75 864 children aged 1-15 years from 2100 communities were included in the analysis. The prevalence of trachomatous inflammation follicular (TF) among these children in surveyed districts was 19.1% (95% CI 17.9-20.2%) in Ethiopia, 6.2% (95% CI 5.4-6.9%) in Niger, 4.6% (95% CI 4.2-4.9%) in Mali and 4.2% (95% CI 3.5-4.9%) in Nigeria. Controlling for age, sex and clustering, the OR of TF for school-attendees compared to non-attendees was 0.64 (95% CI 0.56-0.73) in Ethiopia, 0.67 (95% CI 0.56-0.80) in Mali, 1.03 (95% CI 0.81-1.16) in Niger and 1.06, (95% CI 0.65-1.73) in Nigeria.
  
  
  CONCLUSIONS
  Estimating the prevalence of trachoma through examination of only school-going children risks underestimating the true prevalence.
authors.affiliation: The Carter Center, 1149 Ponce de Leon Ave, Atlanta, GA 30306, USA.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: King
authors.forename: Peter
authors.initials: P
authors.lastname: Odermatt
authors.forename: Jürg
authors.initials: J
authors.lastname: Utzinger
authors.forename: Jeremiah
authors.initials: J
authors.lastname: Ngondi
authors.forename: Sanoussi
authors.initials: S
authors.lastname: Bamani
authors.forename: Yaya
authors.initials: Y
authors.lastname: Kamissoko
authors.forename: Kadri
authors.initials: K
authors.lastname: Boubicar
authors.forename: Adamou Sabo
authors.initials: AS
authors.lastname: Hassan
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Nwobi
authors.forename: Nimzing
authors.initials: N
authors.lastname: Jip
authors.forename: Asrat
authors.initials: A
authors.lastname: Amnie
authors.forename: Tesfaye
authors.initials: T
authors.lastname: Teferi
authors.forename: Aryc W
authors.initials: AW
authors.lastname: Mosher
authors.forename: Aisha E P
authors.initials: AE
authors.lastname: Stewart
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Cromwell
authors.forename: Paul M
authors.initials: PM
authors.lastname: Emerson
mesh_terms: D000293:Adolescent; D000349:Africa / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D005002:Ethiopia / Q000453:epidemiology; D005260:Female; D006306:Health Surveys / Q000379:methods* / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D008297:Male; D008302:Mali / Q000453:epidemiology; D058069:Neglected Diseases / Q000453:epidemiology*; D009548:Niger / Q000453:epidemiology; D009549:Nigeria / Q000453:epidemiology; D015995:Prevalence; D013334:Students / Q000706:statistics & numerical data*; D014141:Trachoma / Q000453:epidemiology*
keywords: Neglected tropical diseases; School attendance; Sub-Sahara Africa; Surveys; Trachoma