Abstract
Purpose: :
As part of the SAFE strategy, a multifaceted trachoma control program, azithromycin is provided to all residents of trachoma hyperendemic communities annually. However, there are no data to advise program managers on how long they need to mass treat to achieve a target prevalence of follicular trachoma (TF) less than 10% in children. The purpose of the study is to determine the effect of variable numbers of years of mass treatment on prevalence of trachoma and C. trachomatous infection in children in trachoma endemic villages.
Methods: :
The Tanzanian National Trachoma Control Program has rolled in Districts, and villages within districts, into their program of mass distribution of azithromycin. Villages eligible for this study had to have a baseline survey for trachoma, known numbers of years of mass treatment, and at least 50% of the mass treatments had data on coverage. We stratified villages into whether they had received 3, 4, 5, 6, or 7 years of mass treatment, and randomly picked approximately 18 villages in each strata. Within villages, after census, we randomly selected at least 100 children and examined them for trachoma and took ocular swabs for C. trachomatis.
Results: :
Rates of trachoma declined according to number of years of mass treatment, at the rate of about 2% per year. There was a steady increase in the percentage of villages in each strata that achieved 10% with number of years of mass treatment, adjusted for baseline prevalence of trachoma; from 17% with 3 years of mass treatment to 86% with 7 years (p=.04). Baseline prevalence, and to a lesser extent, Community Coverage, were important predictors of trachoma. Declines in infection rates were more variable.
Conclusions: :
These data suggest a gradual trajectory for reduction in TF with mass treatment, although periodic surveys will reveal communities that can be graduated to targeted treatment in order to conserve resources.
Keywords: trachoma • antibiotics/antifungals/antiparasitics