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Global elimination of trachoma: How frequently should we administer mass chemotherapy?

Nature Medicine volume 5, pages 572–576 (1999)Cite this article

Abstract

The World Health Organization has recommended repeat mass drug administration as part of their global initiative to eliminate blinding trachoma by the year 2020. The efficacy of repeat treatment will be tested empirically, but the results will not be available for many years, and recommendations for the necessary frequency of treatment are needed immediately. We have developed a mathematical model that uses available epidemiological data from a variety of countries. We recommend, based on our analysis, that in areas where trachoma is moderately prevalent (<35% in children), it should be treated annually, but hyperendemic areas (>50% in children), it should be treated biannually.

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Figure 2: Estimated initial doubling times and necessary treatment periods for various communities.
Figure 3: Simulations of the time course of active trachoma infection (in children 1–10 years old) with repeated mass drug administration.
Figure 4: The necessary frequency of treatments that will ensure the eventual elimination of active trachoma if only individuals under a certain age are treated, based on age prevalences from Malawi.
Figure 1: In this model, individuals of age i are assumed to be either clinically active (that is, by clinical examination, seem to be infected with C. trachomatis) or susceptible.

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Acknowledgements

We thank E. Ziv, H. Gershengorn, K. Koelle, S. Osaki, J.P. Whitcher and J. Schachter fokr comments and A. Edgecombe for technical assostance. We are grateful to the National Institute of Allergy and Infectious Diseases (Grants K08 Al 01-441-0 and 1R01 A1 41935).

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  1. Travis Porco

    Present address: The Department of Public Health, City of San Francisco

Authors and Affiliations

  1. The F.I. Proctor Foundation and the Department of Ophthalmology the University of California San Francisco, San Francisco, California

    Tom Lietman & Chandler Dawson

  2. The Departments of Medicine and Microbiology & Immunology at the University of California San Francisco, San Francisco , California

    Travis Porco & Sally Blower

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Correspondence to Tom Lietman.

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Lietman, T., Porco, T., Dawson, C. et al. Global elimination of trachoma: How frequently should we administer mass chemotherapy?. Nat Med 5, 572–576 (1999). https://doi.org/10.1038/8451

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