Comparison of the most recent prevalence estimates for trachomatous inflammation—Follicular (TF) in 1–9-year-olds, Malawi, in (a) 2014 and (b) 2016 (after the impact surveys reported here, undertaken following one round of azithromycin MDA).

<p>Comparison of the most recent prevalence estimates for trachomatous inflammation—Follicular (TF) in 1–9-year-olds, Malawi, in (a) 2014 and (b) 2016 (after the impact surveys reported here, undertaken following one round of azithromycin MDA).</p

Trachomatous inflammation—Follicular (TF) prevalence at baseline and at impact survey, selected districts, Malawi, 2013–2016.

<p>Trachomatous inflammation—Follicular (TF) prevalence at baseline and at impact survey, selected districts, Malawi, 2013–2016.</p

Evaluation unit population sizes, number of 1–9-year-old children examined, and trachomatous inflammation—Follicular (TF) prevalence in 1–9-year-olds, impact surveys, Malawi, May–August 2016.

<p>Evaluation unit population sizes, number of 1–9-year-old children examined, and trachomatous inflammation—Follicular (TF) prevalence in 1–9-year-olds, impact surveys, Malawi, May–August 2016.</p

One round of azithromycin MDA adequate to interrupt transmission in districts with prevalence of trachomatous inflammation—follicular of 5.0-9.9%: Evidence from Malawi

<div><p>Background</p><p>As highly trachoma-endemic countries approach elimination, some districts will have prevalences of trachomatous inflammation–follicular in 1–9-year-olds (TF_1-9) of 5.0–9.9%. The World Health Organization (WHO) previously recommended that in such districts, TF prevalence be assessed in each sub-district (groupings of at least three villages), with three rounds of azithromycin treatment offered to any sub-district in which TF≥10%. Given the large number of endemic districts worldwide and the human and financial resources required to conduct surveys, this recommendation may not be practical. In a group of 8 Malawi districts with baseline TF prevalences of 5.0–9.9%, the Malawi Ministry of Health administered one round of azithromycin mass treatment, to the whole of each district, achieving mean coverage of ~80%. Here, we report impact surveys conducted after that treatment.</p><p>Methods</p><p>We undertook population-based trachoma surveys in 18 evaluation units of the 8 treated districts, at least 6 months after the MDA. The standardized training package and survey methodologies of Tropical Data, which conform to WHO recommendations, were used.</p><p>Results</p><p>Each of the 18 evaluation units had a TF_1-9 prevalence <5.0%.</p><p>Conclusion</p><p>The study demonstrates that in Malawi districts with TF of 5.0–9.9%, one round of azithromycin MDA with ~80% coverage associates with a reduction in TF prevalence to <5%. Further evidence for this approach should be collected elsewhere.</p></div

Comparative Ct <i>omcB</i> and plasmid load recovered from swabs stored at -20°C (n = 15) and +5°C (n = 15) for the duration of the study (November 2013 –July 2014).

<p>Comparative Ct <i>omcB</i> and plasmid load recovered from swabs stored at -20°C (n = 15) and +5°C (n = 15) for the duration of the study (November 2013 –July 2014).</p

Low Prevalence of Ocular <i>Chlamydia trachomatis</i> Infection and Active Trachoma in the Western Division of Fiji

<div><p>Background</p><p>Trachoma is the leading infectious cause of blindness and is caused by ocular infection with the bacterium <i>Chlamydia trachomatis</i> (Ct). While the majority of the global disease burden is found in sub-Saharan Africa, the Western Pacific Region has been identified as trachoma endemic. Population surveys carried out throughout Fiji have shown an abundance of both clinically active trachoma and trachomatous trichiasis in all divisions. This finding is at odds with the clinical experience of local healthcare workers who do not consider trachoma to be highly prevalent. We aimed to determine whether conjunctival infection with Ct could be detected in one administrative division of Fiji.</p><p>Methods</p><p>A population-based survey of 2306 individuals was conducted using the Global Trachoma Mapping Project methodology. Population prevalence of active trachoma in children and trichiasis in adults was estimated using the World Health Organization simplified grading system. Conjunctival swabs were collected from 1009 children aged 1–9 years. DNA from swabs was tested for the presence of the Ct plasmid and human endogenous control.</p><p>Results</p><p>The prevalence of active trachoma in 1–9 year olds was 3.4%. The age-adjusted prevalence was 2.8% (95% CI: 1.4–4.3%). The unadjusted prevalence of ocular Ct infection in 1–9 year-olds was 1.9% (19/1009), and the age-adjusted infection prevalence was 2.3% (95% CI: 0.4–2.5%). The median DNA load was 41 Ct plasmid copies per swab (min 20, first quartile 32, mean 6665, third quartile 161, max 86354). There was no association between current infection and follicular trachoma. No cases of trachomatous trichiasis were identified.</p><p>Discussion</p><p>The Western Division of Fiji has a low prevalence of clinical trachoma. Ocular Ct infections were observed, but they were predominantly low load infections and were not correlated with clinical signs. Our study data suggest that trachoma does not meet the WHO definition of a public health problem in this Division of Fiji, but the inconsistency with previous studies warrants further investigation.</p></div

Qualitative test for infection in persons with and without clinically active trachoma.

<p>Qualitative test for infection in persons with and without clinically active trachoma.</p

Primer and probe sequences for <i>C</i>.<i>trachomatis</i> targets and control using ddPCR.

<p>[<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004798#pntd.0004798.ref019" target="_blank">19</a>]</p

The four administrative divisions of Fiji, with the selected clusters in the Western division marked as points.

<p>Prepared using ArcGIS 10.2 (ESRI).</p

Normalized optical density (in an ELISA for anti-Pgp3 antibody) in sera from 1–9-year-old children who were positive (red spots in panel (a)) and negative (blue spots in panel (a)) for conjunctival <i>Chlamydia trachomatis</i> infection by droplet digital PCR, Kiritimati Island, Kiribati, November 2015.

<p>In panel (a), the threshold for anti-Pgp3 seropositivity, derived using a finite mixture model, is indicated (dotted line), and within each one-year age band, spots have been moved horizontally in order to separate data points that would otherwise have been superimposed. In panel (b), red lines represent the median values, grey boxes represent inter-quartile ranges, whiskers represent the minima and maxima.</p