title: The burden of trachoma in South Sudan: assessing the health losses from a condition of graded severity.
abstract: BACKGROUND
  Trachoma is a disease that can lead to visual impairment and ultimately blindness. Previous estimates of health losses from trachoma using the Global Burden of Disease methodology have not, however, included the stage prior to visual impairment. We estimated the burden of all stages of trachoma in South Sudan and assessed the uncertainty associated with the severity and duration of stages of trachoma prior to full blindness.
  
  
  METHODS
  The prevalence of trachoma with normal vision, low vision and blindness in the Republic of South Sudan has been estimated previously. These estimates were used to model the incidence and duration of the different stages employing DISMOD II. Different assumptions about disability weights and duration were used to estimate the Years Lived with Disability (YLD).
  
  
  RESULTS
  We have estimated the total burden of trachoma in South Sudan to be between 136,562 and 163,695 YLD and trichiasis with normal vision contributes between 5% and 21% of the total depending on the disability weight applied. Women experience more of this burden than men. The sensitivity of the results to different assumptions about the disability weights is partly dependent upon the assumed duration of the different disease states.
  
  
  CONCLUSIONS
  A better understanding of the natural history of trachoma is critical for a more accurate burden estimate.
authors.affiliation: Institute of Public Health, University of Cambridge, Cambridge, United Kingdom. h.gouda@uq.edu.au
authors.forename: Hebe
authors.initials: H
authors.lastname: Gouda
authors.forename: John
authors.initials: J
authors.lastname: Powles
authors.forename: Jan
authors.initials: J
authors.lastname: Barendregt
authors.forename: Paul
authors.initials: P
authors.lastname: Emerson
authors.forename: Jeremiah
authors.initials: J
authors.lastname: Ngondi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D013397:Sudan / Q000453:epidemiology; D013997:Time Factors; D014141:Trachoma / Q000453:epidemiology* / Q000473:pathology*; D055815:Young Adult