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Modelling Trachoma for Control Programmes

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Modelling Parasite Transmission and Control

Part of the book series: Advances in Experimental Medicine and Biology ((AEMB,volume 673))

Abstract

Trachoma is a major cause of blindness in the developing world and 63 million people are currently infected. Large-scale control programmes are being implemented to clear ocular Chlamydia trachomatis infection—the causative agent of trachoma—and improve environmental conditions to reduce transmission. Chemotherapeutic intervention involves antibiotic administration and the effectiveness of this treatment is currently under investigation. A mathematical model has been developed to allow the impact of control programmes on infection and blinding disease sequelae to be predicted. The model has a structure that allows an important aspect of trachoma pathogenesis to be taken into account, namely the effect of repeated cycles of infection and recovery leading to scarring and the damaging disease sequelae. This novel model structure reproduces many age- and time-dependent epidemiological patterns observed in endemic settings and allows the dynamic effect of treatment on infection and disease sequelae to be gauged.

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References

  1. Resnikoff S, Pascolini D, Etya’ale D et al. Global data on visual impairment in the year 2002. Bull World Health Organ 2004; 82(11):844–851.

    PubMed  Google Scholar 

  2. Molyneux DH, Hotez PJ, Fenwick A. „Rapid-Impact Interventions“: How a policy of integrated control for Africa’s neglected tropical diseases could benefit the poor. PLoS Med 2005; 2(11):e336.

    Article  Google Scholar 

  3. West SK, Munoz B, Mkocha H et al. Infection with Chlamydia trachomatis after mass treatment of a trachoma hyperendemic community in Tanzania: a longitudinal study. Lancet 2005; 366(9493):1296–1300.

    Article  PubMed  Google Scholar 

  4. Burton MJ, Holland MJ, Makalo P et al. Re-emergence of Chlamydia trachomatis infection after mass antibiotic treatment of a trachoma-endemic Gambian community: a longitudinal study. Lancet 2005; 365(9467):1321–1328.

    Article  PubMed  Google Scholar 

  5. Solomon AW, Holland MJ, Alexander ND et al. Mass treatment with single-dose azithromycin for trachoma. N Engl J Med 2004; 351(19):1962–1971.

    Article  CAS  PubMed  Google Scholar 

  6. Anderson R, May R. Infectious Diseases of Humans: Dynamics and Control: Oxford University Press; 1992.

    Google Scholar 

  7. Bailey R, Duong T, Carpenter R et al. The duration of human ocular Chlamydia trachomatis infection is age dependent. Epidemiol Infect 1999; 123(3):479–486.

    Article  CAS  PubMed  Google Scholar 

  8. Taylor HR, Johnson SL, Prendergast RA et al. An animal model of trachoma II. The importance of repeated reinfection. Invest Ophthalmol Vis Sci 1982; 23(4):507–515.

    PubMed  Google Scholar 

  9. Grayston JT, Wang SP, Yeh LJ et al. Importance of reinfection in the pathogenesis of trachoma. Rev Infect Dis 1985; 7(6):717–725.

    CAS  PubMed  Google Scholar 

  10. Detels R, Alexander ER, Dhir SP. Trachoma in Punjabi Indians in British Columbia: a prevalence study with comparisons to India. Am J Epidemiol 1966; 84(1):81–91.

    CAS  PubMed  Google Scholar 

  11. Baral K, Osaki S, Shreshta B et al. Reliability of clinical diagnosis in identifying infectious trachoma in a low-prevalence area of Nepal. Bull World Health Organ 1999; 77(6):461–466.

    CAS  PubMed  Google Scholar 

  12. Hayes LJ, Bailey RL, Mabey DC et al. Genotyping of Chlamydia trachomatis from a trachoma-endemic village in the Gambia by a nested polymerase chain reaction: identification of strain variants. J Infect Dis 1992; 166(5):1173–1177.

    CAS  PubMed  Google Scholar 

  13. Burton MJ, Holland MJ, Faal N et al. Which members of a community need antibiotics to control trachoma? Conjunctival Chlamydia trachomatis infection load in Gambian villages. Invest Ophthalmol Vis Sci 2003; 44(10):4215–4222.

    Article  PubMed  Google Scholar 

  14. Solomon AW, Holland MJ, Burton MJ et al. Strategies for control of trachoma: observational study with quantitative PCR. Lancet 2003; 362(9379):198–204.

    Article  PubMed  Google Scholar 

  15. Wright HR, Taylor HR. Clinical examination and laboratory tests for estimation of trachoma prevalence in a remote setting: what are they really telling us? Lancet Infect Dis 2005; 5(5):313–320.

    Article  PubMed  Google Scholar 

  16. Solomon AW, Peeling RW, Foster A et al. Diagnosis and assessment of trachoma. Clin Microbiol Rev 2004; 17(4):982–1011, table of contents.

    Article  CAS  PubMed  Google Scholar 

  17. Miller K, Schmidt G, Melese M et al. How reliable is the clinical exam in detecting ocular chlamydial infection? Ophthalmic Epidemiol 2004; 11(3):255–262.

    Article  PubMed  Google Scholar 

  18. Burton MJ, Holland MJ, Jeffries D et al. Conjunctival chlamydial 16S ribosomal RNA expression in trachoma: is chlamydial metabolic activity required for disease to develop? Clin Infect Dis 2006; 42(4):463–470.

    Article  CAS  PubMed  Google Scholar 

  19. Lansingh VC, Weih LM, Keeffe JE et al. Assessment of trachoma prevalence in a mobile population in Central Australia. Ophthalmic Epidemiol 2001; 8(2–3):97–108.

    Article  CAS  PubMed  Google Scholar 

  20. Schemann JF, Sacko D, Banou A et al. [Cartography of trachoma in Mali: results of a national survey]. Bull World Health Organ 1998; 76(6):599–606.

    CAS  PubMed  Google Scholar 

  21. Ngondi J, Ole-Sempele F, Onsarigo A et al. Blinding trachoma in postconflict southern Sudan. PLoS Med 2006; 3(12):e478.

    Article  Google Scholar 

  22. Ngondi J, Reacher M, Matthews F et al. The epidemiology of low vision and blindness associated with trichiasis in southern Sudan. BMC Ophthalmol 2007; 7:12.

    Article  PubMed  Google Scholar 

  23. Courtright P. Contribution of sex-linked biology and gender roles to disparities with trachoma. Emerg Infect Dis 2004; 10(11):2012–2016.

    PubMed  Google Scholar 

  24. Cumberland P, Hailu G, Todd J. Active trachoma in children aged three to nine years in rural communities in Ethiopia: prevalence, indicators and risk factors. Trans R Soc Trop Med Hyg 2005; 99(2):120–127.

    Article  PubMed  Google Scholar 

  25. Werner GT, Sareen DK. Trachoma in Punjab: a study of the prevalence and of mass treatment. Trop Geogr Med 1977; 29(2):135–140.

    CAS  PubMed  Google Scholar 

  26. Regassa K, Teshome T. Trachoma among adults in Damot Gale District, South Ethiopia. Ophthalmic Epidemiol 2004; 11(1):9–16.

    Article  PubMed  Google Scholar 

  27. Zerihun N. Trachoma in Jimma zone, south western Ethiopia. Trop Med Int Health 1997; 2(12):1115–1121.

    Article  CAS  PubMed  Google Scholar 

  28. Ramsey KH, Poulsen CE, Motiu PP. The in vitro antimicrobial capacity of human colostrum against Chlamydia trachomatis. J Reprod Immunol 1998; 38(2):155–167.

    Article  CAS  PubMed  Google Scholar 

  29. Brunham RC, Rey-Ladino J. Immunology of Chlamydia infection: implications for a Chlamydia trachomatis vaccine. Nat Rev Immunol 2005; 5(2):149–161.

    Article  CAS  PubMed  Google Scholar 

  30. Bowman RJ, Jatta B, Cham B et al. Natural history of trachomatous scarring in The Gambia: results of a 12-year longitudinal follow-up. Ophthalmology 2001; 108(12):2219–2224.

    Article  CAS  PubMed  Google Scholar 

  31. West SK, Munoz B, Lynch M et al. Risk factors for constant, severe trachoma among preschool children in Kongwa, Tanzania. Am J Epidemiol 1996; 143(1):73–78.

    CAS  PubMed  Google Scholar 

  32. Morrison RP. Chlamydial immunology and vaccinology. Proceedings of the Chlamydia Vaccine Development Colloquium 2003; 19–23.

    Google Scholar 

  33. Stephens RS. The cellular paradigm of chlamydial pathogenesis. Trends Microbiol 2003; 11(1):44–51.

    Article  CAS  PubMed  Google Scholar 

  34. Ward M, Bailey R, Lesley A et al. Persisting inapparent chlamydial infection in a trachoma endemic community in The Gambia. Scand J Infect Dis Suppl 1990; 69:137–148.

    CAS  PubMed  Google Scholar 

  35. West SK, Munoz B, Mkocha H et al. Progression of active trachoma to scarring in a cohort of Tanzanian children. Ophthalmic Epidemiol 2001; 8(2–3):137–144.

    Article  CAS  PubMed  Google Scholar 

  36. Morrison RP. New insights into a persistent problem—chlamydial infections. J Clin Invest 2003; 111(11):1647–1649.

    Article  CAS  PubMed  Google Scholar 

  37. Caldwell HD, Wood H, Crane D et al. Polymorphisms in Chlamydia trachomatis tryptophan synthase genes differentiate between genital and ocular isolates. J Clin Invest 2003; 111(11):1757–1769.

    Article  CAS  PubMed  Google Scholar 

  38. Morrison RP, Caldwell HD. Immunity to murine chlamydial genital infection. Infect Immun 2002; 70(6):2741–2751.

    Article  CAS  PubMed  Google Scholar 

  39. Mabey DCW, Bailey RL, Hutin YJF. The epidemiology and pathogenesis of trachoma. Review of medical microbiology 1992; 3:112–119.

    Google Scholar 

  40. Kumaresan J. Can blinding trachoma be eliminated by 20/20? Eye 2005; 19(10):1067–1073.

    Article  CAS  PubMed  Google Scholar 

  41. Lietman T, Porco T, Dawson C et al. Global elimination of trachoma: how frequently should we administer mass chemotherapy? Nat Med 1999; 5(5):572–576.

    Article  CAS  PubMed  Google Scholar 

  42. Gill DA, Lakew T, Alemayehu W et al. Complete elimination is a difficult goal for trachoma programs in severely affected communities. Clin Infect Dis 2008; 46(4):564–566.

    Article  PubMed  Google Scholar 

  43. Melese M, Alemayehu W, Lakew T et al. Comparison of annual and biannual mass antibiotic administration for elimination of infectious trachoma. JAMA 2008; 299(7):778–784.

    Article  CAS  PubMed  Google Scholar 

  44. Ray KJ, Porco TC, Hong KC et al. A rationale for continuing mass antibiotic distributions for trachoma. BMC Infect Dis 2007; 7:91.

    Article  PubMed  Google Scholar 

  45. Melese M, Chidambaram JD, Alemayehu W et al. Feasibility of eliminating ocular Chlamydia trachomatis with repeat mass antibiotic treatments. JAMA 2004; 292(6):721–725.

    Article  CAS  PubMed  Google Scholar 

  46. Solomon AW, Harding-Esch E, Alexander ND et al. Two doses of azithromycin to eliminate trachoma in a Tanzanian community. N Engl J Med 2008; 358(17):1870–1871.

    Article  CAS  PubMed  Google Scholar 

  47. Grassly N, Ward ME, Ferris S et al. The natural history of trachoma infection and disease in a Gambian cohort with frequent follow-up. PLoS Neglected Tropical Diseases 2008; 2(12): e341.

    Article  Google Scholar 

  48. Boas ML. Mathematical Methods In The Physical Sciences. 2nd ed. New York: John Wiley & Sons, 1983

    Google Scholar 

  49. Gambhir M, Basanez MG, Turner F et al. Trachoma: transmission, infection and control. Lancet Infect Dis 2007; 7(6):420–427.

    Article  PubMed  Google Scholar 

  50. West ES, Munoz B, Mkocha H et al. Mass treatment and the effect on the load of Chlamydia trachomatis infection in a trachoma-hyperendemic community. Invest Ophthalmol Vis Sci 2005; 46(1):83–87.

    Article  PubMed  Google Scholar 

  51. West SK, Munoz B, Mkocha H et al. Trachoma and ocular Chlamydia trachomatis were not eliminated three years after two rounds of mass treatment in a trachoma hyperendemic village. Invest Ophthalmol Vis Sci 2007; 48(4):1492–1497.

    Article  PubMed  Google Scholar 

  52. Schachter J, West SK, Mabey D et al. Azithromycin in control of trachoma. Lancet 1999; 354(9179):630–635.

    Article  CAS  PubMed  Google Scholar 

  53. Bailey RL, Arullendran P, Whittle HC et al. Randomised controlled trial of single-dose azithromycin in treatment of trachoma. Lancet 1993; 342(8869):453–456.

    Article  CAS  PubMed  Google Scholar 

  54. Michel CE, Solomon AW, Magbanua JP et al. Field evaluation of a rapid point-of-care assay for targeting antibiotic treatment for trachoma control: a comparative study. Lancet 2006; 367(9522):1585–1590.

    Article  PubMed  Google Scholar 

  55. Taylor HR. Trachoma grading: a new grading scheme. Rev Int Trach Pathol Ocul Trop Subtrop Sante Publique 1987(64):175–181.

    Google Scholar 

  56. Gambhir M, Basánez M-G, Burton MJ et al. The development of an age-structured model for trachoma transmission dynamics, pathogenesis and control. PLoS Neg Trop Dis, doi:10:1371/journal, pntd.0000462, 2009.

    Google Scholar 

  57. Blake IM, Burton MJ, Bailey RL et al. Estimating household and community transmission of ocular Chlamydia trachomatis. PLoS Neglected Tropical Diseases 2009, 3(3): e401.

    Article  Google Scholar 

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Gambhir, M., Basáñez, MG., Blake, I.M., Grassly, N.C. (2010). Modelling Trachoma for Control Programmes. In: Michael, E., Spear, R.C. (eds) Modelling Parasite Transmission and Control. Advances in Experimental Medicine and Biology, vol 673. Springer, New York, NY. https://doi.org/10.1007/978-1-4419-6064-1_10

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