Dataset Information

The easiest children to reach are most likely to be infected with ocular Chlamydia trachomatis in trachoma endemic areas of Niger.

ABSTRACT:

Background

Control programs for trachoma use mass antibiotic distributions to treat ocular Chlamydia trachomatis in an effort to eliminate this disease worldwide. To determine whether children infected with ocular Chlamydia are more likely to present later for examination than those who are uninfected, we compare the order of presentation for examination of children 0-5 years, and the presence of ocular Chlamydia by PCR in 4 villages in Niger where trachoma is endemic.

Methods

We conducted a cluster-randomized, controlled trial where 48 randomly selected villages in Niger are divided into 4 study arms of different mass treatment strategies. In a substudy of the main trial, we randomly selected 1 village from each of the 4 study arms (4 total villages) and we evaluated the odds of ocular Chlamydia versus the rank order of presentation for examination and laboratory assessment before treatment was offered.

Findings

We found the odds of harboring ocular Chlamydia dropped by more than 70% from the first child examined to the last child examined (OR 0.27, 95% CI 0.13-0.59, P?=?0.001) in the 4 randomly selected villages. We found the odds of active trachoma dropped by 80% from the first child examined to the last child examined (OR 0.20, 95% CI 0.10-0.4, P<0.0001) in the 48 villages in the main trial.

Interpretation

This study demonstrates that even if the WHO recommended 80% treatment coverage is not reached in certain settings, children 0-5 years with the greatest probability of ocular Chlamydia have higher odds of receiving attention because they are the first to present. These results suggest there may be diminishing returns when using scarce resources to track down the last few children in a mass treatment program.

Trial registration

ClinicalTrials.gov NCT00792922.

SUBMITTER: Amza A

PROVIDER: S-EPMC3542188 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

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Publications

The easiest children to reach are most likely to be infected with ocular Chlamydia trachomatis in trachoma endemic areas of Niger.

Amza Abdou A Kadri Boubacar B Nassirou Baido B Yu Sun N SN Stoller Nicole E NE Bhosai Satasuk J SJ Zhou Zhaoxia Z McCulloch Charles E CE West Sheila K SK Bailey Robin L RL Keenan Jeremy D JD Lietman Thomas M TM Gaynor Bruce D BD

PLoS neglected tropical diseases 20130110 1

<h4>Background</h4>Control programs for trachoma use mass antibiotic distributions to treat ocular Chlamydia trachomatis in an effort to eliminate this disease worldwide. To determine whether children infected with ocular Chlamydia are more likely to present later for examination than those who are uninfected, we compare the order of presentation for examination of children 0-5 years, and the presence of ocular Chlamydia by PCR in 4 villages in Niger where trachoma is endemic.<h4>Methods</h4>We ...[more]

PMID: 23326612

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Project description:BackgroundTrachoma, caused by Chlamydia trachomatis, remains the leading infectious cause of blindness worldwide. Persistence and progression of the resulting clinical disease appears to be an immunologically mediated process. Azithromycin, which is distributed at the community level for trachoma control, has immunomodulatory properties. We investigated the impact of one round of oral azithromycin on conjunctival immune responses, C. trachomatis infection and clinical signs three- and six- months post treatment relative to three pre-treatment time-points.MethodologyA cohort of children aged 6 to 10 years were recruited from a trachoma endemic region of northern Tanzania and were visited five times in a 12-month period. They were examined for clinical signs of trachoma and conjunctival swabs were collected for laboratory analysis. C. trachomatis infection was detected and the expression of 46 host genes was quantified using quantitative PCR. All community members were offered azithromycin treatment immediately after the six-month timepoint according to international guidelines.FindingsThe prevalence of C. trachomatis infection and inflammatory disease signs were significantly reduced three- and six- months post-mass drug administration (MDA). C. trachomatis infection was strongly associated with clinical signs at all five time-points. A profound anti-inflammatory effect on conjunctival gene expression was observed 3 months post-MDA, however, gene expression had largely returned to pre-treatment levels of variation by 6 months. This effect was less marked, but still observed, after adjusting for C. trachomatis infection and when the analysis was restricted to individuals who were free from both infection and clinical disease at all five time-points. Interestingly, a modest effect was also observed in individuals who did not receive treatment.ConclusionConjunctival inflammation is the major clinical risk factor for progressive scarring trachoma, therefore, the reduction in inflammation associated with azithromycin treatment may be beneficial in limiting the development of potentially blinding disease sequelae. Future work should seek to determine whether this effect is mediated directly through inhibition of pro-inflammatory intracellular signalling molecules, through reductions in concurrent, sub-clinical infections, and/or through reduction of infection exposure.

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Dataset Information

The easiest children to reach are most likely to be infected with ocular Chlamydia trachomatis in trachoma endemic areas of Niger.

Background

Methods

Findings

Interpretation

Trial registration

Publications

The easiest children to reach are most likely to be infected with ocular Chlamydia trachomatis in trachoma endemic areas of Niger.

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