£3.9m project to support elimination of the world’s leading infectious cause of blindness

A major new research project that aims to accelerate the elimination of trachoma has been launched

Stronger-SAFE is a £3.9m Wellcome Trust funded project that will increase our understanding of how trachoma is transmitted, and hopefully lead to the development and testing of new, more effective interventions and treatment approaches. Professor Nick Thomson, from the Wellcome Trust Sanger Institute and the London School of Hygiene & Tropical Medicine (LSHTM), is part of the team that are using new DNA sequencing approaches to better understand how this disease is spread.

The five year study will take place in Ethiopia where the disease is highly endemic, and be conducted with the London School of Hygiene & Tropical Medicine and partners the Ethiopian Ministry of Health, the Oromia Regional Health Bureau The Fred Hollows Foundation and Monash University in Australia.

Trachoma is an eye disease caused by infection with the bacterium Chlamydia trachomatis. Around 190 million people worldwide live in endemic areas and require treatment. After repeated eye infections, trichiasis develops, a condition where the eyelids turn inwards and the lashes scrape the surface of the eye, causing great pain and often leading to permanent loss of vision.

Trachoma is thought to spread through person-to-person contact and by flies that have been in contact with discharge from the eyes of an infected person. The disease is responsible for 3 per cent of the world’s blindness, with more than 80 per cent of the burden of active trachoma concentrated in 14 Sub-Saharan African countries. Ethiopia is the most severely affected country.

To combat trachoma, the World Health Organization Alliance for the Global Elimination of Trachoma by 2020 (GET2020) recommends the SAFE Strategy: Surgery for trichiasis, mass distribution of the antibiotic azithromycin to treat chlamydial infection, Facial cleanliness and Environmental improvement to suppress transmission. Many endemic countries are implementing SAFE, and there is a major effort to scale-up activities with the aim of eliminating trachoma as a public health problem by 2020.

However, data from hyperendemic regions, areas where trachoma rates are continually high such as Ethiopia, suggest that current approaches do not consistently have the anticipated impact on infection and disease. Antibiotic schedules are not achieving reliable long-term control after treatment is finished and the ‘F&E’ components, such as improving water access, sanitation and hygiene (WASH) and fly-control, are not clearly defined and inconsistently implemented. Detailed studies investigating potential transmission routes and their relative importance have never been conducted, a gap that Stronger-SAFE aims to address.

“Trachoma is a terrible disease. Of the 190 million people who live in areas where it’s endemic, around two million are visually impaired, of whom 500,000 are blind. Although there has been a concerted international effort to tackle the disease, with success in many regions, elimination in highly endemic regions by 2020 is less certain, with recent research suggesting that current methods to control trachoma in these regions aren’t as effective as previously thought.”

Matthew Burton Professor of International Eye Health at the London School of Hygiene & Tropical Medicine, is the project’s Principal Investigator

Stronger-SAFE involves three phases. The first will focus on understanding how trachoma is transmitted in households and communities. Observational studies will document hygiene practice, sleeping arrangements and human behaviour that could promote transmission, as well as evaluating the contribution of fly to eye contact. Working closely with affected communities, Phase 2 aims to develop new approaches to stop the spread of disease, informed by the results from Phase 1. Both of these phases will utilise the latest genomic strategies to study transmission of this disease.

“We are applying modern genomic tools to understand an ancient neglected tropical disease and see how it is transmitted in an endemic area. By implementing a modified SAFE trachoma strategy, and then assessing if it improves the effectiveness of treatment, we will support better evidence-based strategies to defeat trachoma. This will help inform the broader global strategies for the elimination of trachoma by 2020.”

Professor Nick Thomson From the Sanger Institute and LSHTM

The third phase of Stronger-SAFE is a cluster randomised controlled trial. It will test whether a combination of a double-dose of antibiotics and the newly developed facial cleanliness and environmental improvement intervention package from Phase 2, will be more effective than current interventions in the elimination of trachoma.

Stronger-SAFE will be conducted in Oromia, Ethiopia.

“Trachoma is a catastrophic and costly disease for Ethiopia. With more than 70 per cent of districts in Ethiopia currently requiring mass drug administration, more than 73 million people are affected by trachoma – almost 80 per cent of the Ethiopian population.

“The Ethiopian government is committed to eliminating trachoma. Though we are seeing rewarding results we now stand at a point where we need to gather evidence for intensifying our interventions if we are to meet our GET2020 commitments and targets. We believe that Stronger SAFE will provide this much needed evidence that will enable Ethiopia to eliminate trachoma.”

Biruck Kebede Acting Director, Disease Prevention and Control, Federal Ministry of Health, Ethiopia

“Neglected Tropical Diseases like trachoma have a devastating impact, hitting poorest communities hardest. Wellcome is committed to supporting research to better understand and to improve treatments of these diseases. We are delighted to support this study to help eliminate this painful, infectious disease and prevent millions of people losing their sight because of it.”

Erica Pufall From Wellcome’s Population Health team