title: The Global Trachoma Mapping Project: Methodology of a 34-Country Population-Based Study.
abstract: OBJECTIVE
  To complete the baseline trachoma map worldwide by conducting population-based surveys in an estimated 1238 suspected endemic districts of 34 countries.
  
  
  METHODS
  A series of national and sub-national projects owned, managed and staffed by ministries of health, conduct house-to-house cluster random sample surveys in evaluation units, which generally correspond to "health district" size: populations of 100,000-250,000 people. In each evaluation unit, we invite all residents aged 1 year and older from h households in each of c clusters to be examined for clinical signs of trachoma, where h is the number of households that can be seen by 1 team in 1 day, and the product h × c is calculated to facilitate recruitment of 1019 children aged 1-9 years. In addition to individual-level demographic and clinical data, household-level water, sanitation and hygiene data are entered into the purpose-built LINKS application on Android smartphones, transmitted to the Cloud, and cleaned, analyzed and ministry-of-health-approved via a secure web-based portal. The main outcome measures are the evaluation unit-level prevalence of follicular trachoma in children aged 1-9 years, prevalence of trachomatous trichiasis in adults aged 15 + years, percentage of households using safe methods for disposal of human feces, and percentage of households with proximate access to water for personal hygiene purposes.
  
  
  RESULTS
  In the first year of fieldwork, 347 field teams commenced work in 21 projects in 7 countries.
  
  
  CONCLUSIONS
  With an approach that is innovative in design and scale, we aim to complete baseline mapping of trachoma throughout the world in 2015.
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine , London , UK .
authors.forename: Anthony W
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authors.forename: Alexandre L
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authors.forename: Jonathan D
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authors.lastname: Mesurier
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authors.forename: Thomas M
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authors.forename: Anna
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authors.lastname: Massey
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authors.forename: Addis
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authors.lastname: Mekasha
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authors.lastname: Millar
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authors.forename: Beatriz E
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authors.forename: Jeremiah
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authors.lastname: Ngondi
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authors.lastname: Ogden
authors.forename: Joseph
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authors.lastname: Pearce
authors.forename: Virginia
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authors.lastname: Sarah
authors.forename: Alemayehu
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authors.lastname: Sisay
authors.forename: Jennifer L
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authors.lastname: Smith
authors.forename: Hugh R
authors.initials: HR
authors.lastname: Taylor
authors.forename: Jo
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authors.lastname: Thomson
authors.forename: Sheila K
authors.initials: SK
authors.lastname: West
authors.forename: Rebecca
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authors.lastname: Willis
authors.forename: Simon
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authors.lastname: Haddad
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mesh_terms: D000293:Adolescent; D001766:Blindness / Q000517:prevention & control; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D018672:Community Health Planning; D019353:Endemic Diseases / Q000706:statistics & numerical data*; D005260:Female; D014943:Global Health; D006306:Health Surveys; D006801:Humans; D006920:Hygiene / Q000592:standards; D007223:Infant; D008297:Male; D015995:Prevalence; D012499:Sanitation / Q000592:standards; D014141:Trachoma / Q000453:epidemiology*; D058457:Trichiasis / Q000453:epidemiology*; D014881:Water Supply / Q000592:standards
keywords: Blindness; mHealth; prevalence study; trachoma; trichiasis