Mass Drug Administration for Trachoma: How Long Is Not Long Enough?

• Type of Material: Article
• Authors: Violeta Jimenez, Emory University; Huub C. Gelderblom, Emory University; Rebecca Mann Flueckiger, Emory University; Paul M. Emerson, Emory University; Danny Haddad, Emory University
• Language: English
• Date: 2015-03-23
• Publisher: Public Library of Science
• Publication Version: Final Published Version
• Copyright Statement: © 2015 Jimenez et al.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1371/journal.pntd.0003610
• Title of Journal or Parent Work: PLoS Neglected Tropical Diseases
• ISSN: 1935-2727
• Volume: 9
• Issue: 3
• Start Page: e0003610
• End Page: e0003610
• Grant/Funding Information: DH was partially supported by an unrestricted departmental grant from Research to Prevent Blindness (RPB).; VJ thanks the Dean’s Council of the Rollins School of Public Health for supporting her work with a Robert W. Woodruff Fellowship.; We acknowledge the Bill and Melinda Gates Foundation for financial support to ITI.
• Research Categories: Health Sciences, Opthamology; Health Sciences, Public Health

Abstract

Background: Blinding trachoma is targeted for elimination by 2020 using the SAFE strategy (Surgery, Antibiotics, Facial cleanliness, and Environmental improvements). Annual mass drug administration (MDA) with azithromycin is a cornerstone of this strategy. If baseline prevalence of clinical signs of trachomatous inflammation – follicular among 1-9 year-olds (TF1-9) is ≥10% but <30%, the World Health Organization guidelines are for at least 3 annual MDAs; if ≥30%, 5. We assessed the likelihood of achieving the global elimination target of TF1-9 <5% at 3 and 5 year evaluations using program reports. Methodology/Principal Findings: We used the International Trachoma Initiative’s prevalence and treatment database. Of 283 cross-sectional survey pairs with baseline and follow-up data, MDA was conducted in 170 districts. Linear and logistic regression modeling was applied to these to investigate the effect of MDA on baseline prevalence. Reduction to <5% was less likely, though not impossible, at higher baseline TF1-9 prevalences. Increased number of annual MDAs, as well as no skipped MDAs, were significant predictors of reduced TF1-9 at follow-up. The probability of achieving the <5% target was <50% for areas with ≥30% TF1-9 prevalence at baseline, even with 7 or more continuous annual MDAs. Conclusions: Number of annual MDAs alone appears insufficient to predict program progress; more information on the effects of baseline prevalence, coverage, and underlying environmental and hygienic conditions is needed. Programs should not skip MDAs, and at prevalences >30%, 7 or more annual MDAs may be required to achieve the target. There are five years left before the 2020 deadline to eliminate blinding trachoma. Low endemic settings are poised to succeed in their elimination goals. However, newly-identified high prevalence districts warrant immediate inclusion in the global program. Intensified application of the SAFE strategy is needed in order to guarantee blinding trachoma elimination by 2020.