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

Spatial clusters of non-participation.

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

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

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

Estimated examination and testing cost per EA in the study EAs and across the study area, by costing category (USD).

<p>Estimated examination and testing cost per EA in the study EAs and across the study area, by costing category (USD).</p

Prevalence of <i>C.trachomatis</i> infection^* in children aged 1 to 9 years by village.

<p>*<i>C. trachomatis</i> infection detected by Amplicor.</p>†<p>Village 12 withdrew after 17 months.</p

The prevalence of <i>Chlamydia trachomatis</i> infection* in children aged 1 to 9 years for the 14 villages^†.

<p>Individual villages are represented by the grey lines. Several villages overlie each other with a prevalence of 0%. The overall village level average is represented by the black line. *<i>Chlamydia trachomatis</i> infection determined by Amplicor CT PCR assay. ^†Village No. 12 withdrew after 17-months.</p

<i>Chlamydia trachomatis</i> infection load.

<p>*The individual infection load is the geometric mean and 95% CI of the <i>C. trachomatis</i> infection load expressed in copies of <i>ompA</i>/swab, for all infected individuals in the study population.</p>†<p>The community load of infection is the Williams Mean for the study population (including uninfected individuals), expressed in copies of the <i>ompA</i>/swab.</p