Map of The Gambia indicating the boundaries of the trachoma surveillance zones.

<p>Map of The Gambia indicating the boundaries of the trachoma surveillance zones.</p

Prevalence of TF in children aged 1 to 9 years by surveillance zone in years 2011 to 2013.

<p>Prevalence of TF in children aged 1 to 9 years by surveillance zone in years 2011 to 2013.</p

Location of the study districts within The Gambia.

<p>Dark grey: study districts, pale grey: remaining districts of The Gambia.</p

Multilevel univariable random effects logistic regression analysis of factors associated with ocular <i>C. trachomatis</i> infection.

a<p>Unadjusted (crude) Odds Ratio (cOR) using two-level univariable mixed effects logistic regression; CI = confidence interval.</p>b<p>p-value for Wald test (Wald's Chi²); significant associations (where <i>p≤0.05</i>) are highlighted in bold.</p>c<p>Continuous numeric variables.</p>d<p>reported by household head.</p>e<p>a ‘vasilha’ is a vessel of capacity ∼30 litres.</p>f<p>researcher observed.</p>g<p>researcher observed within 15 m of the household.</p

The relationship between trachoma and presence of infection with <i>C. trachomatis</i> (<i>Ct</i>).

a<p>N = total number and % = proportion.</p>b<p>Using the WHO Simplified Grading System where TF = trachomatous inflammation-follicular, TI = trachomatous inflammation-intense, TS = trachomatous scarring <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002900#pntd.0002900-Thylefors1" target="_blank">[23]</a>. Individuals may appear in more than one clinical category.</p>c<p><i>Ct</i> DNA detected (<i>Ct</i>+) or absent (<i>Ct</i>−) by Amplicor PCR.</p

Multivariable models for <b>EBA</b> versus treated children.

<p>Multivariable models for <b>EBA</b> versus treated children.</p

Multilevel univariable random effects logistic regression analysis of factors associated with active trachoma^a.

a<p>Active trachoma defined as TF (inflammatory trachoma-follicular) and/or TI (inflammatory trachoma-intense) using the WHO simplified scoring system <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002900#pntd.0002900-Thylefors1" target="_blank">[23]</a>.</p>b<p>Unadjusted (crude) Odds Ratio (cOR) from two-level univariable mixed effects logistic regression analyses; CI = confidence interval.</p>c<p>p-value for Wald test (Wald's Chi²); significant associations (where <i>p≤0.05</i>) are highlighted in bold.</p>d<p>Continuous numeric variables.</p>e<p>reported by household head.</p>f<p>a ‘vasilha’ is a vessel of capacity ∼30 litres.</p>g<p>researcher observed.</p>h<p>researcher observed within 15 m of the household.</p

Multilevel multivariable random effects logistic regression analysis of factors associated with ocular <i>C. trachomatis</i> infection.

a<p>Adjusted Odds Ratio (aOR) using two-level multivariable mixed effects logistic regression modelling; CI = confidence interval.</p>b<p>p-value for Wald test (Wald's Chi²); significant associations (where <i>p≤0.05</i>) are highlighted in bold.</p>c<p>researcher observed.</p

Spatial clusters of non-participation.

<p>Spatial clusters of non-participation.</p

Spatial clusters of PNT and EBA children aged 1–9 years on the North river bank.

<p>A: baseline treatment round, B: year one, C: year two. Treated (grey), PNT (red), EBA (blue), PNT cluster (pink), EBA cluster (light blue). No PNT children at year one or year two in study districts north of the river. Location of children aged 0–5 years with <i>C. trachomatis</i> infection at year three (green).</p