title: Targeting trachoma control through risk mapping: the example of Southern Sudan.
abstract: BACKGROUND
  Trachoma is a major cause of blindness in Southern Sudan. Its distribution has only been partially established and many communities in need of intervention have therefore not been identified or targeted. The present study aimed to develop a tool to improve targeting of survey and control activities.
  
  
  RESULTS
  A national trachoma risk map was developed using Bayesian geostatistics models, incorporating trachoma prevalence data from 112 geo-referenced communities surveyed between 2001 and 2009. Logistic regression models were developed using active trachoma (trachomatous inflammation follicular and/or trachomatous inflammation intense) in 6345 children aged 1-9 years as the outcome, and incorporating fixed effects for age, long-term average rainfall (interpolated from weather station data) and land cover (i.e. vegetation type, derived from satellite remote sensing), as well as geostatistical random effects describing spatial clustering of trachoma. The model predicted the west of the country to be at no or low trachoma risk. Trachoma clusters in the central, northern and eastern areas had a radius of 8 km after accounting for the fixed effects.
  
  
  CONCLUSIONS
  In Southern Sudan, large-scale spatial variation in the risk of active trachoma infection is associated with aridity. Spatial prediction has identified likely high-risk areas to be prioritized for more data collection, potentially to be followed by intervention.
authors.affiliation: School of Population Health, University of Queensland, Herston, Queensland, Australia.
authors.forename: Archie C A
authors.initials: AC
authors.lastname: Clements
authors.forename: Lucia W
authors.initials: LW
authors.lastname: Kur
authors.forename: Gideon
authors.initials: G
authors.lastname: Gatpan
authors.forename: Jeremiah M
authors.initials: JM
authors.lastname: Ngondi
authors.forename: Paul M
authors.initials: PM
authors.lastname: Emerson
authors.forename: Mounir
authors.initials: M
authors.lastname: Lado
authors.forename: Anthony
authors.initials: A
authors.lastname: Sabasio
authors.forename: Jan H
authors.initials: JH
authors.lastname: Kolaczinski
mesh_terms: D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D002980:Climate; D005260:Female; D005843:Geography; D006801:Humans; D007223:Infant; D008297:Male; D015233:Models, Statistical; D015995:Prevalence; D012307:Risk Factors; D012308:Risk Management; D013397:Sudan / Q000453:epidemiology; D014141:Trachoma / Q000453:epidemiology* / Q000517:prevention & control*
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