Largest-ever infectious disease survey completed on trachoma

A three-year disease-mapping project that concluded last month has reported that 100 million people are at risk of blindness as a result of trachoma.

The £10.6m Global Trachoma Mapping Project (GTMP) was launched in December 2012 and is the largest infectious disease survey to have been undertaken, with surveyors collecting data using Android smartphones from 2.6 million people across 29 countries.

Funded by the UK government’s Department of International Development (DFID), the project was led by Sightsavers in collaboration with 30 ministries of health which supported the work through staff, technical support, supervision and vehicles.

The project aimed to pinpoint trachoma endemic areas accurately around the world, and during the mapping, 29 at risk countries were identified, including Ethiopia, which has the world’s highest prevalence of the disease and where more than 50 million people are living in endemic areas.

More than 550 teams of trained surveyors visited millions of households in countries such as Chad, Eritrea, Pakistan, Papua New Guinea, the Solomon Islands, Colombia and Yemen. They performed eye examinations and used mobile phones to record their results. The findings were then sent to a data centre in the US, where it was analysed before being sent to local governments for review, approval and use.

GTMP project director, Siobhain McCullagh, said a variety of initiatives were needed to fight trachoma. Providing antibiotics was one key factor, but educating communities on what to do to avoid the spread of the disease and when to seek medical attention was just as important, she said, adding:
“We had [trachoma] in the UK and Ireland. The problem wasn’t solved with antibiotics. It was solved through improved hygiene."

The fight against trachoma would already be boosted by the fact the GTMP team had screened 2.6 million individuals and educated them about how to treat and stop the spread of the infection, Ms McCullagh explained. “Those individuals when meeting with their community will talk about trachoma,” she said. 

She also emphasised that along with crippling physical symptoms, including photophobia, trachoma had life-long economic implications: "It reduces the ability of people to work and means that children have to look after dependents."

Sightsavers reports that, on average, one person was examined every 40 seconds during the three-year project.

CEO of Sightsavers, Dr Caroline Harper, confirmed that the project was completed in the agreed timescales and budget. She added: “Funded by the UK government, in partnership with the US and World Health Organization (WHO), this creates a lasting platform which will underpin the drive to eliminate other neglected tropical diseases. It demonstrates how critical accurate data is in the battle to eliminate diseases, and has been a tremendous exercise in collaboration and the use of mobile technology.”

She emphasised that along with crippling physical symptoms, including photophobia, trachoma had life-long economic implications: “It reduces the ability of people to work and means that children have to look after dependents."

The data has been recorded on a Trachoma Atlas and offers ministries of health in endemic countries an evidence base to inform health strategies to tackle trachoma. Labelled as a neglected tropical disease, WHO approved interventions include surgery, antibiotics, face-cleanliness and environmental improvements.

Trachoma is responsible for 3% of the world’s blindness and is a condition caused by chlamydia trachomatis. It is believed to spread through personal contact and by flies.