Trachoma.

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 (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.