Stronger SAFE

Trachoma, a blinding eye disease caused by repeated infection by the bacterium Chlamydia trachomatis (Ct), remains a significant public health problem in Ethiopia despite years of implementation of the SAFE strategy for trachoma control. The SAFE strategy involves Surgery for trichiasis, Antibiotics (azithromycin) to treat Ct infection, Facial cleanliness and Environmental improvements to suppress transmission.

There is growing evidence that current approaches are not having the anticipated impact on infection and disease. This is a significant threat to the timely elimination of trachoma. The five year, Wellcome Trust funded ‘Stronger-SAFE’ research programme aims to use cutting edge molecular tools alongside detailed clinical, epidemiological, observational and entomological methods to try to better understand and define transmission of trachoma, and to develop and test novel, contextually appropriate interventions to interrupt transmission towards elimination trachoma.

The programme aims to build technical capacity in Oromia, including establishing molecular laboratory testing for Ct. It is unclear which, if any, F&E measures currently applied programmatically suppress transmission. Stronger-SAFE Phase 1 sought to improve our understanding of potential transmission routes. Our field research team collected swabs from eyes, faces, hands, clothing, bed linen, a variety of household objects and eye-seeking flies captured from the faces of young children and tested these samples for the presence of Ct. We found Ct on faces, hands and some clothing. Eye-seeking flies (Musca Sorbens) are thought to be a passive vector for trachoma. This was the first study to demonstrate the presence of Ct on M. Sorbens flies caught from the faces of children in Oromia. Stronger-SAFE Phase 2 involves developing approaches to interrupt these transmission routes. Following detailed observational research we are focusing on face washing to remove Ct-carrying discharge from faces and hands.

This research shows that discharge can be more effectively removed when faces are washed with soap than when they are washed with water only. We are exploring the utility of insect repellents and fly traps to keep eye-seeking flies away from children’s faces. The final F&E intervention package will be tested in a large cluster randomised trial in the Stronger-SAFE Phase 3 and will include face washing promotion, prototype ‘fly-repellent headwear’ (caps and scarves) and a fly trap. This ‘enhanced’ F&E package in addition to double dose azithromycin will form the ‘Stronger-SAFE’ strategy, which will be compared to ‘standard’ SAFE implementation in the clinical trial.