Trachoma is a preventable blinding condition that accounts for 10-15% of blindness worldwide. It is caused by bacterial infection (Chlamydia trachomatis) of the conjunctiva and is common in dry regions of central Africa. Eradication of trachoma (with use of appropriate antibiotics and promotion of facial cleanliness) by 2020 was targeted as a public-health priority by WHO five years ago. The main issue for eradication of trachoma is identification of the true prevalence of the infection, and prioritising prevention and treatment strategies to appropriate target groups.
David Mabey from the London School of Hygiene and Tropical Medicine, UK, and colleagues did specific genetic analysis (polymerase chain reaction, or PCR) of C Trachomatis from eye swabs of over 3000 individuals in two highly endemic areas in Tanzania and one area of The Gambia. 90% of trachoma infections were among children younger than 10 years in the two Tanzanian areas studied. Around half of individuals (including children and adults) had conjunctival scarring due to trachoma infection in the areas with the highest trachoma prevalence.
In a seminar also published in this week's issue (p 198), David Mabey and colleagues discuss WHO's "SAFE" strategy for the control of trachoma: surgery for in-turned lashes, antibiotics for active disease, facial cleanliness, and environmental improvement (including access to safe drinking water and reducing overcrowded living conditions). The authors comment that the development of azithromycin for treatment of trachoma (a single oral dose of azithromycin is as effective as 6 weeks of topical tetracycline) has been an important advance in trachoma control. They also outline how implementation of the "SAFE" strategy is the key to the elimination of trachoma by 2020.
An accompanying Commentary (p 181) by Hugh Taylor from the University of Melbourne, Australia, welcomes the important step forward in the use of genetic analysis (by PCR) to quantify the extent of trachoma infection. He concludes: "…the future possibilities are both exciting and challenging. Undoubtedly this future will lead to a greater understanding of the transmission of trachoma and kindle further interest and effort to eliminate this ancient blinding disease."
Issue 19 July 2003 (pp 181, 198, 223)
Embargoed 0001 h (London time) 18 July 2003. In North America, the embargo time for Lancet press material is 6:30pm ET Thursday 17 July 2003.
Contact: Professor David CW Mabey, Department of Clinical Sciences, London School of Hygiene &Tropical Medicine, Keppel Street, London, WC1E 7HT, UK; T) +44 (20) 7927 2297; F) +44 (20) 7637 4314; E) david.mabey@lshtm.ac.uk
Professor Hugh R Taylor, Centre for Eye Research Australia, University of Melbourne, East Melbourne 3002, Australia; T) +61 3 9929 8368; F) +61 3 9662 3859; E) h.taylor@unimelb.edu.au
Journal
The Lancet