Diagnostic Characteristics of Tests for Ocular Chlamydia after Mass Azithromycin Distributions
Open Access
- 1 January 2012
- journal article
- research article
- Published by Association for Research in Vision and Ophthalmology (ARVO) in Investigative Ophthalmology & Visual Science
- Vol. 53 (1), 235-240
- https://doi.org/10.1167/iovs.11-8493
Abstract
Purpose.: Although trachoma control programs frequently use the World Health Organization (WHO) simplified grading system for trachoma to monitor the clinical response after repeated mass azithromycin treatments, the programmatic relevance of this evaluation after multiple rounds of antibiotic treatments is unclear. Methods.: Three rounds of annual mass azithromycin were distributed to 12 villages in Ethiopia. Twelve months after the third treatment, children were assessed for follicular trachomatous inflammation (TF) and intense trachomatous inflammation (TI) using the WHO simplified grading system and for ocular chlamydial infection using DNA-based and RNA-based tests. Test characteristics for predicting chlamydial infection were computed assuming a chlamydial RNA-based gold standard. As a secondary analysis, test characteristics were also assessed using a latent class analysis. Results.: The prevalence of RNA evidence of ocular chlamydia was 7.1% (95% confidence interval [CI], 2.7–17.4). A DNA-based test and TF had sensitivities of 61.0% (95% CI, 47.1–73.3) and 65.9% (95% CI, 41.6–83.9), specificities of 100% (95% CI, 99.3–100) and 67.5% (95% CI, 61.0–73.5), and positive predictive values of 100% (95% CI, 86.3–100) and 13.4% (95% CI, 5.5–29.3) compared with an RNA-based gold standard. The latent class analysis confirmed that the RNA-based test was a reasonable choice for a gold standard, with a sensitivity of 100% (95% CI, 67.1–100) and specificity of 99.6% (95% CI, 98.1–100). Conclusions.: Basing treatment decisions after mass azithromycin distributions on the WHO simplified grading system will maximize the treatment of infected persons compared with a DNA-based test but will also result in more uninfected persons being treated. The RNA-based test was considerably more sensitive, and almost equivalently specific, compared with a DNA-based test. (ClinicalTrials.gov number, NCT00322972.)This publication has 40 references indexed in Scilit:
- Chlamydial infection during trachoma monitoring: are the most difficult‐to‐reach children more likely to be infected?Tropical Medicine & International Health, 2011
- Ribosomal RNA Evidence of Ocular Chlamydia trachomatis Infection Following 3 Annual Mass Azithromycin Distributions in Communities With Highly Prevalent TrachomaClinical Infectious Diseases, 2011
- How Reliable Are Tests for Trachoma?—A Latent Class ApproachInvestigative Ophthalmology & Visual Science, 2011
- Efficacy of latrine promotion on emergence of infection with ocular Chlamydia trachomatis after mass antibiotic treatment: a cluster-randomized trialInternational Health, 2011
- Trachoma Prevalence and Associated Risk Factors in The Gambia and Tanzania: Baseline Results of a Cluster Randomised Controlled TrialPLoS Neglected Tropical Diseases, 2010
- Performance of Three Nucleic Acid Amplification Tests for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae by Use of Self-Collected Vaginal Swabs Obtained via an Internet-Based Screening ProgramJournal of Clinical Microbiology, 2009
- Reduction and Return of Infectious Trachoma in Severely Affected Communities in EthiopiaPLoS Neglected Tropical Diseases, 2009
- Abilities of APTIMA, AMPLICOR, and ProbeTec Assays To Detect Chlamydia trachomatis and Neisseria gonorrhoeae in PreservCyt ThinPrep Liquid-Based Pap SamplesJournal of Clinical Microbiology, 2007
- Comparison of an rRNA-based and DNA-based nucleic acid amplification test for the detection of Chlamydia trachomatis in trachomaBritish Journal of Ophthalmology, 2006
- Detection of Chlamydia trachomatis by Nucleic Acid Amplification Testing: Our Evaluation Suggests that CDC-Recommended Approaches for Confirmatory Testing Are Ill-AdvisedJournal of Clinical Microbiology, 2006