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Ramadhani AM, Derrick T, Macleod D, Holland MJ, Burton MJ. The Relationship between Active Trachoma and Ocular Chlamydia trachomatis Infection before and after Mass Antibiotic Treatment. PLoS Negl Trop Dis 2016; 10:e0005080. [PMID: 27783678 PMCID: PMC5082620 DOI: 10.1371/journal.pntd.0005080] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 09/28/2016] [Indexed: 12/02/2022] Open
Abstract
Background Trachoma is a blinding disease, initiated in early childhood by repeated conjunctival infection with the obligate intracellular bacterium Chlamydia trachomatis. The population prevalence of the clinical signs of active trachoma; ‘‘follicular conjunctivitis” (TF) and/or ‘‘intense papillary inflammation” (TI), guide programmatic decisions regarding the initiation and cessation of mass drug administration (MDA). However, the persistence of TF following resolution of infection at both the individual and population level raises concerns over the suitability of this clinical sign as a marker for C. trachomatis infection. Methodology/Principle Findings We systematically reviewed the literature for population-based studies and those including randomly selected individuals, which reported the prevalence of the clinical signs of active trachoma and ocular C. trachomatis infection by nucleic acid amplification test. We performed a meta-analysis to assess the relationship between active trachoma and C. trachomatis infection before and after MDA. TF and C. trachomatis infection were strongly correlated prior to MDA (r = 0.92, 95%CI 0.83 to 0.96, p<0.0001); the relationship was similar when the analysis was limited to children. A moderate correlation was found between TI and prevalence of infection. Following MDA, the relationship between TF and infection prevalence was weaker (r = 0.60, 95%CI 0.25 to 0.81, p = 0.003) and there was no correlation between TI and C. trachomatis infection. Conclusions/Significance Prior to MDA, TF is a good indicator of the community prevalence of C. trachomatis infection. Following MDA, the prevalence of TF tends to overestimate the underlying infection prevalence. In order to prevent unnecessary additional rounds of MDA and to accurately ascertain when elimination goals have been reached, a cost-effective test for C. trachomatis that can be administered in low-resource settings remains desirable. Trachoma is the leading infectious cause of blindness worldwide, caused by the bacterium Chlamydia trachomatis. Repeated infection of the conjunctiva during childhood can initiate chronic conjunctival inflammation. This can lead to conjunctival scarring, in turning of the eyelashes, abrasion of the eyelashes on the cornea and eventually blindness later in adulthood. The World Health Organization recommends mass drug administration (MDA) for infection control when the prevalence of the clinical sign of Active Trachoma (TF) is ≥10% in 1–9 year olds. This systematic review of the literature examined the relationship between TF and C. trachomatis infection before and after MDA in order to evaluate the usefulness of TF for guiding trachoma control programmes. The population prevalence of TF and C. trachomatis infection were strongly correlated prior to MDA, however the relationship was weaker after MDA with a greater tendency for TF to overestimate the underlying infection prevalence. A cost effective test for C. trachomatis suitable for use in low resource settings could prevent unnecessary additional rounds of MDA in the population and could identify when trachoma elimination goals have been reached at an earlier time point.
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Affiliation(s)
- Athumani M. Ramadhani
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, United Kingdom
- Kilimanjaro Christian Medical Centre, Moshi, Tanzania
- * E-mail:
| | - Tamsyn Derrick
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, United Kingdom
- Kilimanjaro Christian Medical Centre, Moshi, Tanzania
| | - David Macleod
- Tropical Epidemiology Group. London School of Hygiene & Tropical Medicine, United Kingdom
| | - Martin J. Holland
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, United Kingdom
| | - Matthew J. Burton
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
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Butcher RMR, Sokana O, Jack K, Macleod CK, Marks ME, Kalae E, Sui L, Russell C, Tutill HJ, Williams RJ, Breuer J, Willis R, Le Mesurier RT, Mabey DCW, Solomon AW, Roberts CH. Low Prevalence of Conjunctival Infection with Chlamydia trachomatis in a Treatment-Naïve Trachoma-Endemic Region of the Solomon Islands. PLoS Negl Trop Dis 2016; 10:e0004863. [PMID: 27603015 PMCID: PMC5014345 DOI: 10.1371/journal.pntd.0004863] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 06/29/2016] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Trachoma is endemic in several Pacific Island states. Recent surveys across the Solomon Islands indicated that whilst trachomatous inflammation-follicular (TF) was present at levels warranting intervention, the prevalence of trachomatous trichiasis (TT) was low. We set out to determine the relationship between chlamydial infection and trachoma in this population. METHODS We conducted a population-based trachoma prevalence survey of 3674 individuals from two Solomon Islands provinces. Participants were examined for clinical signs of trachoma. Conjunctival swabs were collected from all children aged 1-9 years. We tested swabs for Chlamydia trachomatis (Ct) DNA using droplet digital PCR. Chlamydial DNA from positive swabs was enriched and sequenced for use in phylogenetic analysis. RESULTS We observed a moderate prevalence of TF in children aged 1-9 years (n = 296/1135, 26.1%) but low prevalence of trachomatous inflammation-intense (TI) (n = 2/1135, 0.2%) and current Ct infection (n = 13/1002, 1.3%) in children aged 1-9 years, and TT in those aged 15+ years (n = 2/2061, 0.1%). Ten of 13 (76.9%) cases of infection were in persons with TF or TI (p = 0.0005). Sequence analysis of the Ct-positive samples yielded 5/13 (38%) complete (>95% coverage of reference) genome sequences, and 8/13 complete plasmid sequences. Complete sequences all aligned most closely to ocular serovar reference strains. DISCUSSION The low prevalence of TT, TI and Ct infection that we observed are incongruent with the high proportion of children exhibiting signs of TF. TF is present at levels that apparently warrant intervention, but the scarcity of other signs of trachoma indicates the phenotype is mild and may not pose a significant public health threat. Our data suggest that, whilst conjunctival Ct infection appears to be present in the region, it is present at levels that are unlikely to be the dominant driving force for TF in the population. This could be one reason for the low prevalence of TT observed during the study.
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Affiliation(s)
- Robert M. R. Butcher
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Oliver Sokana
- Eye Department, Solomon Islands Ministry of Health and Medical Services, Honiara, Solomon Islands
| | - Kelvin Jack
- Eye Department, Solomon Islands Ministry of Health and Medical Services, Honiara, Solomon Islands
| | - Colin K. Macleod
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Sightsavers, Haywards Heath, United Kingdom
| | - Michael E. Marks
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Hospital for Tropical Diseases, University College London Hospitals, London, United Kingdom
| | - Eric Kalae
- Primary Care Department, Lata Hospital, Lata, Santa Cruz, Solomon Islands
| | - Leslie Sui
- Primary Care Department, Lata Hospital, Lata, Santa Cruz, Solomon Islands
| | | | - Helena J. Tutill
- Division of Infection & Immunity, Faculty of Medical Sciences, University College London, London, United Kingdom
| | - Rachel J. Williams
- Division of Infection & Immunity, Faculty of Medical Sciences, University College London, London, United Kingdom
| | - Judith Breuer
- Division of Infection & Immunity, Faculty of Medical Sciences, University College London, London, United Kingdom
| | - Rebecca Willis
- Task Force for Global Health, Decatur, Georgia, United States of America
| | - Richard T. Le Mesurier
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - David C. W. Mabey
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Hospital for Tropical Diseases, University College London Hospitals, London, United Kingdom
| | - Anthony W. Solomon
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Chrissy h. Roberts
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Liu F, Porco TC, Mkocha HA, Muñoz B, Ray KJ, Bailey RL, Lietman TM, West SK. The efficacy of oral azithromycin in clearing ocular chlamydia: mathematical modeling from a community-randomized trachoma trial. Epidemics 2014; 6:10-7. [PMID: 24593917 PMCID: PMC4420489 DOI: 10.1016/j.epidem.2013.12.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 12/05/2013] [Accepted: 12/11/2013] [Indexed: 11/29/2022] Open
Abstract
Mass oral azithromycin distributions have dramatically reduced the prevalence of the ocular strains of chlamydia that cause trachoma. Assessing efficacy of the antibiotic in an individual is important in planning trachoma elimination. However, the efficacy is difficult to estimate, because post-treatment laboratory testing may be complicated by nonviable organisms or reinfection. Here, we monitored ocular chlamydial infection twice a year in pre-school children in 32 communities as part of a cluster-randomized clinical trial in Tanzania (prevalence in children was lowered from 22.0% to 4.7% after 3-year of annual treatment). We used a mathematical transmission model to estimate the prevalence of infection immediately after treatment, and found the effective field efficacy of antibiotic in an individual to be 67.6% (95% CI: 56.5–75.1%) in this setting. Sensitivity analyses suggested that these results were not dependent on specific assumptions about the duration of infection. We found no evidence of decreased efficacy during the course of the trial. We estimated an 89% chance of elimination after 10 years of annual treatment with 95% coverage.
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Affiliation(s)
- Fengchen Liu
- F.I. Proctor Foundation, University of California, San Francisco, CA, USA
| | - Travis C Porco
- F.I. Proctor Foundation, University of California, San Francisco, CA, USA; Department of Ophthalmology, University of California, San Francisco, CA, USA; Department of Epidemiology & Biostatistics, University of California, San Francisco, CA, USA.
| | | | - Beatriz Muñoz
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Kathryn J Ray
- F.I. Proctor Foundation, University of California, San Francisco, CA, USA
| | - Robin L Bailey
- Faculty of Infectious and Tropical Diseases, Clinical Research Department, London School of Hygiene & Tropical and Medicine, London, UK
| | - Thomas M Lietman
- F.I. Proctor Foundation, University of California, San Francisco, CA, USA; Department of Ophthalmology, University of California, San Francisco, CA, USA; Department of Epidemiology & Biostatistics, University of California, San Francisco, CA, USA; Institute for Global Health, University of California, San Francisco, CA, USA
| | - Sheila K West
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD, USA
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Lavett DK, Lansingh VC, Carter MJ, Eckert KA, Silva JC. Will the SAFE strategy be sufficient to eliminate trachoma by 2020? Puzzlements and possible solutions. ScientificWorldJournal 2013; 2013:648106. [PMID: 23766701 PMCID: PMC3671555 DOI: 10.1155/2013/648106] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 03/13/2013] [Indexed: 11/18/2022] Open
Abstract
Since the inception of (the Global Elimination of Blinding Trachoma) GET 2020 in 1997 and the implementation of the SAFE strategy a year later, much progress has been made toward lowering the prevalence of trachoma worldwide with elimination of the disease in some countries. However, high recurrence of trichiasis after surgery, difficulty in controlling the reemergence of infection after mass distribution of azithromycin in some communities, the incomplete understanding of environment in relation to the disease, and the difficulty in establishing the prevalence of the disease in low endemic areas are some of the issues still facing completion of the GET 2020 goals. In this narrative review, literature was searched from 1998 to January 2013 in PubMed for original studies and reviews. Reasons for these ongoing problems are discussed, and several suggestions are made as avenues for exploration in relation to improving the SAFE strategy with emphasis on improving surgical quality and management of the mass treatment with antibiotics. In addition, more research needs to be done to better understand the approach to improve sanitation, hygiene, and environment. The main conclusion of this review is that scale-up is needed for all SAFE components, and more research should be generated from communities outside of Africa and Asia.
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Affiliation(s)
- Diane K. Lavett
- Strategic Solutions, Inc., 1143 Salsbury Avenue, Cody, WY 82414, USA
| | - Van C. Lansingh
- International Agency for the Prevention of Blindness/VISION 2020 Latin America, 3720 San Simeon Circle, Weston, FL 33331, USA
- Hamilton Eye Institute, University of Memphis, Memphis, TN 38152, USA
| | - Marissa J. Carter
- Strategic Solutions, Inc., 1143 Salsbury Avenue, Cody, WY 82414, USA
| | - Kristen A. Eckert
- Strategic Solutions, Inc., 1143 Salsbury Avenue, Cody, WY 82414, USA
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Abstract
PURPOSE OF REVIEW To review recent clinical and epidemiological studies regarding the prevention, diagnosis, and treatment of trachoma. RECENT FINDINGS Newer studies propose novel diagnostic tests that appear sensitive for the detection of ocular chlamydial infection. For example, recent studies with ribosomal RNA-based nucleic acid amplification tests (NAATs) have demonstrated improved sensitivities compared to DNA-based NAATs; and the progression of scarring has now been characterized with confocal microscopy. Immunologic studies have further explored the etiology of clinical sequelae, suggesting that chronic inflammation can lead to progressive scarring even in the absence of Chlamydia. Mass oral azithromycin distributions remain a mainstay of treatment; studies have assessed the appropriate frequency and duration of treatment programs. Current studies have also explored ancillary effects of azithromycin distribution on mortality and bacterial infections. SUMMARY Trachoma programs have had remarkable success at reducing chlamydial infection and clinical signs of trachoma. Recent work suggests improved methods to monitor infection and scarring, and better ways to distribute treatment. Whereas studies continue to demonstrate reduction in infection in hyperendemic areas, more work is necessary to achieve elimination of this blinding disease.
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Amza A, Kadri B, Nassirou B, Yu SN, Stoller NE, Bhosai SJ, Zhou Z, McCulloch CE, West SK, Bailey RL, Keenan JD, Lietman TM, Gaynor BD. The easiest children to reach are most likely to be infected with ocular Chlamydia trachomatis in trachoma endemic areas of Niger. PLoS Negl Trop Dis 2013; 7:e1983. [PMID: 23326612 PMCID: PMC3542188 DOI: 10.1371/journal.pntd.0001983] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 11/07/2012] [Indexed: 11/18/2022] Open
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.
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Affiliation(s)
- Abdou Amza
- Programme National de Lutte Contre la Cecité, Niamey, Niger
| | - Boubacar Kadri
- Programme National de Lutte Contre la Cecité, Niamey, Niger
| | - Baido Nassirou
- Programme National de Lutte Contre la Cecité, Niamey, Niger
| | - Sun N. Yu
- F.I. Proctor Foundation, University of California San Francisco, San Francisco, California, United States of America
| | - Nicole E. Stoller
- F.I. Proctor Foundation, University of California San Francisco, San Francisco, California, United States of America
| | - Satasuk J. Bhosai
- F.I. Proctor Foundation, University of California San Francisco, San Francisco, California, United States of America
| | - Zhaoxia Zhou
- F.I. Proctor Foundation, University of California San Francisco, San Francisco, California, United States of America
| | - Charles E. McCulloch
- Department of Epidemiology & Biostatistics, University of California San Francisco, San Francisco, California, United States of America
| | - Sheila K. West
- Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Robin L. Bailey
- Clinical Research Unit, Department of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Jeremy D. Keenan
- F.I. Proctor Foundation, University of California San Francisco, San Francisco, California, United States of America
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
| | - Thomas M. Lietman
- F.I. Proctor Foundation, University of California San Francisco, San Francisco, California, United States of America
- Department of Epidemiology & Biostatistics, University of California San Francisco, San Francisco, California, United States of America
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
- Institute for Global Health, University of California San Francisco, San Francisco, California, United States of America
| | - Bruce D. Gaynor
- F.I. Proctor Foundation, University of California San Francisco, San Francisco, California, United States of America
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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Keenan JD, See CW, Moncada J, Ayele B, Gebre T, Stoller NE, McCulloch CE, Porco TC, Gaynor BD, Emerson PM, Schachter J, Lietman TM. Diagnostic characteristics of tests for ocular Chlamydia after mass azithromycin distributions. Invest Ophthalmol Vis Sci 2012; 53:235-40. [PMID: 22159017 DOI: 10.1167/iovs.11-8493] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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.).
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Affiliation(s)
- Jeremy D Keenan
- F. I. Proctor Foundation, 513 Parnassus Avenue, Med Sci S309, Box 0412, University of California, San Francisco, San Francisco, CA 94143-0412, USA.
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