Volume 74, Issue 3
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645


We evaluated the reliability of photographs to verify field diagnoses of active trachoma. We examined 956 residents of a trachoma-endemic village for signs of trachoma using the World Health Organization simplified grading system. Two photographs of the right eye of 948 persons were independently graded (masked to field assessment) by the field examiner and two other experienced graders. There was only moderate agreement between field assessment and the subsequent photographic evaluations by the three graders. When we counted ungradable photographs as disagreements, mean kappa scores for the signs trachomatous inflammation (follicular [TF]) and trachomatous inflammation (intense [TI]) were 0.44 and 0.51, respectively. There was also only fair-to-moderate agreement between the three assessments (by different examiners) of the photographs. Either the signs TF and TI themselves are not as reliable as previously believed, or photographs should be used for their diagnosis only when reliability testing demonstrates better agreement than found here.


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  1. Resnikoff S, Pascolini D, Etya’ale D, Kocur I, Pararajasegaram R, Pokharel GP, Mariotti SP, 2004. Global data on visual impairment in the year 2002. Bull World Health Organ 82 : 844–851.
  2. World Health Organization, 1997. Planning for the Global Elimination of Trachoma (GET): Report of a WHO Consultation. (WHO/PBL/97.60). Geneva: World Health Organization.
  3. Kuper H, Solomon AW, Buchan J, Zondervan M, Foster A, Mabey D, 2003. A critical review of the SAFE strategy for the prevention of blinding trachoma. Lancet Infect Dis 3 : 372–381.
  4. Thylefors B, Dawson CR, Jones BR, West SK, Taylor HR, 1987. A simple system for the assessment of trachoma and its complications. Bull World Health Organ 65 : 477–483.
  5. Taylor HR, West SK, Katala S, Foster A, 1987. Trachoma: evaluation of a new grading scheme in the United Republic of Tanzania. Bull World Health Organ 65 : 485–488.
  6. West SK, Taylor HR, 1990. Reliability of photographs for grading trachoma in field studies. Br J Ophthalmol 74 : 12–13.
  7. Siegel S, Castellan NJ, 1988. Nonparametric Statistics for the Behavioral Sciences. New York: McGraw-Hill.
  8. Landis JR, Koch GG, 1977. The measurement of observer agreement for categorical data. Biometrics 33 : 159–174.
  9. Taylor HR, Siler JA, Mkocha HA, Munoz B, Velez V, Dejong L, West S, 1991. Longitudinal study of the microbiology of endemic trachoma. J Clin Microbiol 29 : 1593–1595.
  10. Taylor HR, Siler JA, Mkocha HA, Munoz B, West S, 1992. The natural history of endemic trachoma: a longitudinal study. Am J Trop Med Hyg 46 : 552–559.
  11. Baral K, Osaki S, Shreshta B, Panta CR, Boulter A, Pang F, Cevallos V, Schachter J, Lietman T, 1999. Reliability of clinical diagnosis in identifying infectious trachoma in a low-prevalence area of Nepal. Bull World Health Organ 77 : 461–466.
  12. Holm SO, Jha HC, Bhatta RC, Chaudhary JS, Thapa BB, Davis D, Pokhrel RP, Yinghui M, Zegans M, Schachter J, Frick KD, Tapert L, Lietman TM, 2001. Comparison of two azithromycin distribution strategies for controlling trachoma in Nepal. Bull World Health Organ 79 : 194–200.
  13. Bowman RJ, Sillah A, van Dehn C, Goode VM, Muquit M, Johnson GJ, Milligan P, Rowley J, Faal H, Bailey RL, 2000. Operational comparison of single-dose azithromycin and topical tetracycline for trachoma. Invest Ophthalmol Vis Sci 41 : 4074–4079.
  14. Laming AC, Currie BJ, DiFrancesco M, Taylor HR, Mathews JD, 2000. A targeted, single-dose azithromycin strategy for trachoma. Med J Aust 172 : 163–166.
  15. Thein J, Zhao P, Liu H, Xu J, Jha H, Miao Y, Pizzarello L, Tapert L, Schachter J, Mabon M, Osaki-Holm S, Lietman T, Paxton A, 2002. Does clinical diagnosis indicate ocular chlamydial infection in areas with a low prevalence of trachoma? Ophthalmic Epidemiol 9 : 263–269.
  16. Emerson PM, Lindsay SW, Alexander N, Bah M, Dibba SM, Faal HB, Lowe KO, McAdam KP, Ratcliffe AA, Walraven GE, Bailey RL, 2004. Role of flies and provision of latrines in trachoma control: cluster-randomised controlled trial. Lancet 363 : 1093–1098.
  17. Taylor HR, Rapoza PA, West S, Johnson S, Munoz B, Katala S, Mmbaga BB, 1989. The epidemiology of infection in trachoma. Invest Ophthalmol Vis Sci 30 : 1823–1833.
  18. West SK, Munoz B, Lynch M, Kayongoya A, Mmbaga BB, Taylor HR, 1996. Risk factors for constant, severe trachoma among preschool children in Kongwa, Tanzania. Am J Epidemiol 143 : 73–78.
  19. West S, Munoz B, Lynch M, Kayongoya A, Chilangwa Z, Mmbaga BB, Taylor HR, 1995. Impact of face-washing on trachoma in Kongwa, Tanzania. Lancet 345 : 155–158.
  20. Hsieh Y, Bobo LD, Quinn TC, West SK, 2001. Determinants of trachoma endemicity using Chlamydia trachomatis ompA DNA sequencing. Microbes Infect 3 : 447–458.
  21. Hsieh YH, Bobo LD, Quinn TO, West SK, 2000. Risk factors for trachoma: 6-year follow-up of children aged 1 and 2 years. Am J Epidemiol 152 : 204–211.
  22. Solomon AW, Holland MJ, Burton MJ, West SK, Alexander ND, Aguirre A, Massae PA, Mkocha H, Munoz B, Johnson GJ, Peeling RW, Bailey RL, Foster A, Mabey DC, 2003. Strategies for control of trachoma: observational study with quantitative PCR. Lancet 362 : 198–204.
  23. Bailey R, Osmond C, Mabey DC, Whittle HC, Ward ME, 1989. Analysis of the household distribution of trachoma in a Gambian village using a Monte Carlo simulation procedure. Int J Epidemiol 18 : 944–951.
  24. Solomon AW, Holland MJ, Alexander ND, Massae PA, Aguirre A, Natividad-Sancho A, Molina S, Safari S, Shao JF, Courtright P, Peeling RW, West SK, Bailey RL, Foster A, Mabey DC, 2004. Mass treatment with single-dose azithromycin for trachoma. N Engl J Med 351 : 1962–1971.
  25. Freudenstein U, Verne J, 2001. A national screening programme for diabetic retinopathy. Needs to learn the lessons of existing screening programmes. BMJ 323 : 4–5.
  26. Olson JA, Strachan FM, Hipwell JH, Goatman KA, McHardy KC, Forrester JV, Sharp PF, 2003. A comparative evaluation of digital imaging, retinal photography and optometrist examination in screening for diabetic retinopathy. Diabet Med 20 : 528–534.

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  • Received : 18 May 2005
  • Accepted : 28 Sep 2005

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