Eliminating blinding trachoma through single dose treatment

Research carried out at the School has had a major impact on the elimination of trachoma: the world’s leading cause of preventable blindness.

When David Mabey, professor of communicable diseases at the School, and Robin Bailey, professor of tropical medicine, began to study trachoma in the early 1990s the recommended treatment was tetracycline 1% ointment, administered twice daily to both eyes for six weeks. Few affected individuals completed the course.

In 1993 Mabey and Bailey published the results of a randomised controlled trial in The Gambia, which showed that a single oral dose of azithromycin was as effective as a carefully monitored course of the standard treatment. However, reinfection was common.

They set up a multicentre study in collaboration with Johns Hopkins University and the University of California at San Francisco, which showed that mass treatment with the oral antibiotic was as good as or better than mass treatment with the ointment.

Two clinical PhD fellows were then recruited who did further studies on the impact of mass treatment with azithromycin. Anthony Solomon, who is now in charge of the Global Trachoma Elimination Programme at WHO, eliminated the disease from an endemic village in Tanzania with a single round of treatment, with no-one infected in the village five years later. Matthew Burton, now reader at the International Centre for Eye Health at the School, found a similar effect from a single dose but highlighted the dangers of cross-border mobility in reintroducing infection. The team has continued to work with the Gambian National Eye Care Programme, and WHO trachoma elimination targets were reached in The Gambia in 2013.

As a result of the first two studies, the researchers persuaded the drug company Pfizer to donate azithromycin and it has so far given away 350 million doses to 21 countries. The research also prompted the World Health Organization (WHO) to establish a global elimination programme and launch its SAFE strategy for the control of the disease: surgery, mass treatment with antibiotics in the form of azithromycin, face washing and environmental improvements, such as sanitation.

The School’s body of research has played a significant part in the reduction of the global burden of trachoma: according to WHO the number of cases of active trachoma in the world has plummeted from 150 million in 1995 to 40 million in 2012, with the number of people blinded by the disease falling from 6 million to 1.2 million over the same period.