Trachoma

Overview

General background | Focus of the review | Comments on evidence | Search and appraisal summary | Substantive changes at this update | Abstract | Cite as

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General background

Although trachoma has been controlled in many areas, it is still responsible for 1% of blindness and visual impairment worldwide, according to data from the Global Burden of Disease (GBD) study and the World Health Organisation (WHO). Therefore, it is extremely important to carefully weigh the evidence of interventions that will prevent recurrent infections and frame them in a cost-efficient way, so that authorities can properly invest in an era of many competing health priorities.

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Focus of the review

In previous versions of this overview, we included an evaluation of the evidence for effects of eye lid surgery for treating entropion and triachiasis. However, in this update, we instead have focused on other selected interventions to help answer the clinical question: What are the effects of interventions to prevent scarring trachoma by reducing the prevalence of active trachoma?

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Comments on evidence

A number of very well-conducted studies have been added to the pool of knowledge since the last update of this overview for the clinical question: What are the effects of interventions to prevent scarring trachoma by reducing the prevalence of active trachoma? This is particularly the case with respect to the use of antibiotics. Clinical questions concerning antibiotics for trachoma that remain less than adequately answered include: How long should mass distribution of antibiotics continue when hypoendemic levels have been reached? How should antibiotics be distributed (i.e., should it just be a matter of targeted distribution)? General difficulties with research and evaluation of the evidence in this field include the paucity of high-quality RCTs, particularly those that include sanitation and hygiene interventions, different diagnostic criteria and outcome measures used, the lack of a standard to define a clean face, the frequent difficulty in monitoring progression from scarring to trichiasis and, hence, to corneal opacity in large populations, and the applicability of data from specific communities to other communities in different settings.

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Search and appraisal summary

The update literature search for this overview was carried out from the date of the last search, January 2007, to December 2014. For more information on the electronic databases searched and criteria applied during assessment of studies for potential relevance to the overview, please see the Methods section. Searching of electronic databases retrieved 170 studies. After deduplication and removal of conference abstracts, 96 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 61 studies and the further review of 35 full publications. Of the 35 full articles evaluated, three previously included systematic reviews were updated, one systematic review and two RCTs were added at this update, and two RCTs and one further report were added the Comment sections.

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Additional information

There is evidence for a strong association between trachomatous trichiasis and relative poverty, lending further evidence that general improvements and successful implementation of the SAFE strategy (a set of four interventions recommended by WHO in order to eliminate blinding trachoma as a public health problem) might improve both health and wealth of individuals and communities. The SAFE strategy has been implemented as part of trachoma control policies all over the world. Mathematical models have been developed to analyse the impact of each of the components of the SAFE strategy on disease sequelae.[1]

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Substantive changes at this update

Antibiotics One already reported systematic review updated[17] and one systematic review added.[18] Two RCTs added to the Comment section.[20][21] Categorisation changed from 'unknown effectiveness' to 'likely to be beneficial'.

Face washing alone One already reported systematic review updated.[27] Categorisation unchanged (unknown effectiveness).

Face washing plus topical antibiotics One already reported systematic review updated.[27] Categorisation unchanged (likely to be beneficial).

Fly control through the provision of pit latrines One already reported systematic review updated[33] with one RCT added.[34] One further report of an RCT added to Comment section.[35] Categorisation unchanged (unknown effectiveness).

Fly control using insecticide alone One already reported systematic review updated.[33] Categorisation unchanged (likely to be beneficial).

Fly control using insecticide plus mass antibiotic treatment One already reported systematic review updated.[33] Categorisation unchanged (unknown effectiveness).

Health education One already reported systematic review updated[33] with one RCT added.[38] Categorisation unchanged (unknown effectiveness).

Abstract

INTRODUCTION: Active trachoma is caused by chronic infection of the conjunctiva by Chlamydia trachomatis, and is the world's leading infectious cause of blindness. Infection can lead to: scarring of the tarsal conjunctiva; inversion of the eyelashes (trichiasis), so that they abrade the cornea; and corneal opacity, resulting in blindness. Trachoma is a disease of poverty, overcrowding, and poor sanitation. Active disease affects mainly children, but adults are at increased risk of scarring. METHODS AND OUTCOMES: We conducted a systematic overview, aiming to answer the following clinical question: What are the effects of interventions to prevent scarring trachoma by reducing the prevalence of active trachoma? We searched: Medline, Embase, The Cochrane Library and other important databases up to December 2014 (BMJ Clinical Evidence overviews are updated periodically; please check our website for the most up-to-date version of this overview). RESULTS: At this update, searching of electronic databases retrieved 170 studies. After deduplication and removal of conference abstracts, 96 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 61 studies and the further review of 35 full publications. Of the 35 full articles evaluated, three previously included systematic reviews were updated, one systematic review and two RCTs were added at this update, and two RCTs and one further report were added the Comment sections. We performed a GRADE evaluation for nine PICO combinations. CONCLUSIONS: In this systematic overview, we categorised the efficacy for seven interventions based on information about the effectiveness and safety of antibiotics, face washing (alone or plus topical tetracycline), fly control (through the provision of pit latrines, and using insecticide alone or plus antibiotics), and health education.

Cite as

Lansingh VC. Trachoma. Systematic review 706. BMJ Clinical Evidence. . 2016 February. Accessed [date].

Latest citations

Face washing promotion for preventing active trachoma. ( 20 January 2016 )

Face washing promotion for preventing active trachoma. ( 20 January 2016 )