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The global trachoma mapping project: Methodology of a 34-country population-based study.


PURPOSE: 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.

CONCLUSION: With an approach that is innovative in design and scale, we aim to complete baseline mapping of trachoma throughout the world in 2015.

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Journal Article
Solomon AW
Pavluck AL
Courtright P
Aboe A
Adamu L
Alemayehu W
Alemu M
Alexander ND E
Kello AB
Bero B
Brooker SJ
Chu BK
Dejene M
Emerson PM
Flueckiger RM
Gadisa S
Gass K
Gebre T
Habtamu Z
Harvey E
Haslam D
King JD
Mesurier RL
Lewallen S
Lietman TM
Macarthur C
Mariotti SP
Massey A
Mathieu E
Mekasha A
Millar T
Mpyet C
Muñoz BE
Ngondi J
Ogden S
Pearce J
Sarah V
Sisay A
Smith JL
Taylor HR
Thomson J
West SK
Willis R
Bush S
Haddad D
Foster A
Year of Publication
Ophthalmic epidemiology
Number of Pages
ISSN Number
Alternate Journal
Ophthalmic Epidemiol
Publication Language