title: Mass drug administration for trachoma: how long is not long enough?
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.
  
  
  RESULTS
  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.
authors: Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America; International Trachoma Initiative, Task Force for Global Health, Emory University, Atlanta, Georgia, United States of America; Global Ophthalmology Emory, Emory Eye Center, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors: Violeta
authors: V
authors: Jimenez
authors: International Trachoma Initiative, Task Force for Global Health, Emory University, Atlanta, Georgia, United States of America.
authors: Huub C
authors: HC
authors: Gelderblom
authors: International Trachoma Initiative, Task Force for Global Health, Emory University, Atlanta, Georgia, United States of America.
authors: Rebecca
authors: R
authors: Mann Flueckiger
authors: International Trachoma Initiative, Task Force for Global Health, Emory University, Atlanta, Georgia, United States of America.
authors: Paul M
authors: PM
authors: Emerson
authors: Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America; Global Ophthalmology Emory, Emory Eye Center, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors: Danny
authors: D
authors: Haddad
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D017963:Azithromycin / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D060740:Disease Eradication / Q000379:methods* / Q000706:statistics & numerical data; D004777:Environment; D006801:Humans; D006920:Hygiene; D007223:Infant; D008297:Male; D065129:Pre-Exposure Prophylaxis / Q000379:methods*; D015995:Prevalence; D012044:Regression Analysis; D014141:Trachoma / Q000188:drug therapy* / Q000453:epidemiology*; D014944:World Health Organization
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin