Sightsavers/Peter Nicholls

Global Trachoma Mapping Project

With thanks to SightSavers International for contributing this article

Trachoma is the leading infectious cause of blindness in the world, impairing the vision of around 2.2 million people, of whom 1.2 million are irreversibly blind. It is a health problem in around 51 countries, including Asia and the Middle East, with Africa carrying the bulk of the burden.

The disease is mostly prevalent in poor, crowded communities with limited access to clean water and sanitation. In its initial stages, it mainly passes between children aged one to five, and the women who care for them.

Intrepid researchers have spent three years crossing snowy mountain ranges, islands and vast expanses of desert to check the eyes of 2.6 million people for the eye disease, trachoma.

The Global Trachoma Mapping Project (GTMP) is the largest disease survey ever undertaken and has found more than 100 million people are at risk of the blinding infection.

Trachoma is spread easily from person to person by touch, or by flies. Repeated infection causes the eyelashes to turn inwards and scrape the eye, causing pain with each blink and eventually leading to blindness.

Sightsavers/Peter Nicholls

Android smart phones were used to collect data. Scientific processes, training, data cleaning and approval were standardised across the 29 countries, enabling the project to work at unprecedented scale and cost effectiveness. In addition to individual-level demographic and clinical data, household-level water, sanitation and hygiene data are entered into the purpose-built LINKS application on Android smartphones, transmitted to the Cloud, and cleaned, analysed and ministry of health approved via a secure web-based portal. Each piece of data is geo-references using the global positioning feature of the phone. This method has significantly increased the quality of data collected.

The work is led by Sightsavers with participation from more than 60 partners working together around the world. This work is funded by the Department for International Development (£10.6 million) with additional support from USAID.

Caleb Mpyet, ophthalmologist and GTMP epidemiologist, Nigeria, said:

“It’s been frustrating for health workers in the past knowing there were huge areas of Nigeria where we had no idea of the scale of the trachoma problem, meaning intervention was patchy.
The value of this project was the speed we got the results and the vast areas covered. We now know exactly how trachoma impacts people’s lives and we can use the data to plan our intervention.
Personally, I feel great relief. This project is the best thing that has happened in recent time. We will prevent many people from going blind.”

To explore the interactive data maps from this project follow the link below.

Further Information

Sightsavers/Kate Holt