Number of clusters per district with zero, one, or more than one child antibody positive.

<p>Number of clusters per district with zero, one, or more than one child antibody positive.</p

Percent of antibody positivity stratified by age and district.

<p>Percent of antibody positivity stratified by age and district.</p

The World Health Organization Recommendations for Trachoma Surveillance, Experience in Nepal and Added Benefit of Testing for Antibodies to <i>Chlamydia trachomatis</i> pgp3 Protein: NESTS Study

<div><p>Background</p><p>The World Health Organization (WHO) now requires a second surveillance survey for trachoma after an impact assessment has found follicular trachoma (TF) <5% to determine if re-emergence has occurred. <i>Using</i> new WHO guidelines, we undertook surveillance surveys, and determined the prevalence of infection and antibody positivity, in two districts in Nepal.</p><p>Methods</p><p>20 clusters were randomly selected within each district, 15 were randomly selected for antibody testing. In each cluster, we randomly selected 50 children ages 1–9 years and 100 adults ≥15 years. TF and trachomatous trichiasis (TT) were evaluated. Conjunctival swabs to test for chlamydial infection using GenXpert platform were obtained, and dried blood spots were collected to test for antibodies to <i>Chlamydia Trachomatis</i> pgp3 using the Luminex platform.</p><p>Findings</p><p>3 cases of TF were found in the two districts, and one case of infection. Pgp3 antibody positivity was 2·4% (95% confidence interval: 1·4%, 3·7%), and did not increase with age (<i>P</i> = 0.24). No clustering of antibody positivity within communities was found. TT prevalence was <1/1,000 population.</p><p>Interpretation</p><p>The surveillance surveys, as proposed by WHO, showed no evidence for re-emergence of trachoma in two districts of Nepal. The low level and no significant increase by age in seroprevalence of antibodies to <i>C trachomatis</i> pgp3 antigen deserve further investigation as a marker of interruption of transmission.</p></div

Log MFI–BG value for antibody to pgp3, distributed by age.

<p>The red line corresponds to the cut-off value for positivity. Of the 30 clusters studied, 17 (57%) had no antibody positivity, 8 (27%) had just one child positive, and 5 (16%) had two to three children antibody positive. No cluster had more than 3 children who were antibody positive (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005003#pntd.0005003.g002" target="_blank">Fig 2</a>). There was no evidence that children who were antibody positive clustered within community (ICC 95% Confidence interval: 0·05 (-0·21, 0·32), <i>P</i> = 0·68).</p

Trichiasis and TT in adults ≥15 years old stratified by district.

<p>Trichiasis and TT in adults ≥15 years old stratified by district.</p

Control of Trachoma from Achham District, Nepal: A Cross-Sectional Study from the Nepal National Trachoma Program

<div><p>Background</p><p>The WHO seeks to control trachoma as a public health problem in endemic areas. Achham District in western Nepal was found to have TF (trachoma follicular) above 20% in a 2006 government survey, triggering 3 annual mass drug administrations finishing in 2010. Here we assess the level of control that has been achieved using surveillance for clinical disease, ocular chlamydia trachomatis infection, and serology for antibodies against chlamydia trachomatis protein antigens.</p><p>Methods</p><p>We conducted a cross-sectional survey of children aged 1–9 years in communities in Achham District in early 2014 including clinical examination validated with photographs, conjunctival samples for <i>Chlamydia trachomatis</i> (Amplicor PCR), and serological testing for antibodies against chlamydia trachomatis protein antigens pgp3 and CT694 using the Luminex platform.</p><p>Findings</p><p>In 24 randomly selected communities, the prevalence of trachoma (TF and/or TI) in 1–9 year olds was 3/1124 (0.3%, 95% CI 0.1 to 0.8%), and the prevalence of ocular chlamydia trachomatis infection was 0/1124 (0%, 95% CI 0 to 0.3%). In 18 communities selected because they had the highest prevalence of trachoma in a previous survey, the prevalence of TF and/or TI was 7/716 (1.0%, 95% CI 0.4 to 2.0%) and the prevalence of ocular chlamydia trachomatis infection was 0/716 (0%, 95% CI 0 to 0.5%). In 3 communities selected for serological testing, the prevalence of trachoma was 0/68 (0%, 95% CI 0 to 5.3%), the prevalence of ocular chlamydia trachomatis infection was 0/68 (0%, 95% CI 0 to 0.5%), the prevalence of antibodies against chlamydia trachomatis protein antigen pgp3 was 1/68 (1.5%, 95% CI 0.04% to 7.9%), and the prevalence of antibodies against chlamydia trachomatis protein antigen CT694 was 0/68 (0%, 95% CI 0 to 5.3%).</p><p>Conclusion/Significance</p><p>This previously highly endemic district in Nepal has little evidence of recent clinical disease, chlamydia trachomatis infection, or serological evidence of trachoma, suggesting that epidemiological control has been achieved.</p></div

Prevalence of trachoma, infection and antibodies against <i>C</i>. <i>trachomatis</i> protein antigens in examination, high-prevalence and serology arms.

<p>Community means with 95% CIs.</p

Participant flow.

<p>Participant flow.</p

Baseline characteristics of communities in examination, high-prevalence and serology arms.

<p>Baseline characteristics of communities in examination, high-prevalence and serology arms.</p

Sierra Leone base data (FY Oct. 2010–Sept. 2011).

<p>Sierra Leone base data (FY Oct. 2010–Sept. 2011).</p