Layered maps, real-time data to fight blindness

Layered maps, real-time data to fight blindness


Researchers combine Android and GIS software to visually assess the prevalence of trachoma in remote regions of Africa and to pinpoint gaps in prevention and treatment services

Trachoma is a bacterial infection which produces a characteristic roughening of the inner surface of the eyelids, and is the leading cause of infectious blindness in the world. The disease affects the poorest of the poor — mostly women and children — especially in regions that have limited success to sanitation and water. More people suffer from trachoma in Africa than in any other continent. And because this bacterial disease is transmitted via close personal contact, it tends to occur in clusters — often affecting entire families and communities.

The problem

Approximately 110 million people globally live in endemic areas and require treatment, with 210 million more living where trachoma is suspected of being endemic, according to the International Trachoma Initiative (ITI). “Affected people are said to be living beyond the end of the road,” says Dr Danny Haddad, Director of the ITI. “In some instances, you need to walk half a day to get to some of these villages.”

Until recently, a better ability to identify enclaves of so-called neglected tropical diseases — such as leprosy, river blindness, lymphatic filariasis (elephentiasis), African sleeping sickness, and trachoma — has proved elusive. Fortunately, researchers combining Android and Esri software have figured out a quick way to visually assess the prevalence of trachoma in remote regions and to pinpoint gaps in prevention and treatment services.

A map showing Trachoma’s spread in districts of Ethiopia

The solution

A study of the data collection on trachoma infection, transfer, and visual display process was launched in mid-October 2012 in the Oromia region of Ethiopia. It is part of a global survey founded by the UK government and led by the international non-governmental organisation Sightsavers, which aims to examine a sample of 4 million people across more than 30 countries by March 2015 to identify where people are at the risk of contracting trachoma.

In Ethiopia, several layers of smartphone and GIS technology enabled the immediate transfer of vast amounts of collected data to distant hardware and software platforms for display, analysis and sharing. ArcGIS maps are not only useful as visual tools but also offer real-time transfer of data and automated updates that provide much needed efficiencies, says epidemiologist Alex Pavluck, a senior manager of research information technology at International Trachoma Initiative. “We wanted the ability to produce layered maps. These are really the key here — to show prevalence overlaid with areas currently receiving treatments such as donated drugs.”

The goal was to help realise an ambitious plan endorsed by the World Health Organisation (WHO) for mapping endemic countries with organised national trachoma control programmes, called the Global Elimination of Trachoma by the year 2020, or GET2020.

How it works

According to Haddad, the technology enhanced system was built on one already developed for a variety of neglected tropical diseases, including trachoma. A robust reporting back and allowed data to be sent via cellular network or Wi-Fi to a Web-based system at Task Force headquarters. It didn’t take long for this approach to achieve surprising results, transmitting data on lymphatic filariasis from 18 countries.

“Before we used the Android tools, we had piles of paper that had to be manually entered after a survey,” recalls Haddad. Initial success encouraged public health workers in endemic countries to realise that a system such as this was needed to reach WHO’s GET2020.

Global Atlas of Trachoma, developed in 2011 by the International Trachoma Initiative with the support of partners such as the London School of Hygiene and Tropical Medicine, the Carter Center, and the Bill & Melinda Gates Foundation, provided up-to-date regional maps of trachoma’s geographic distribution.

Nevertheless, researchers discovered that the database supporting the atlas identified more than 1,200 health districts that still lacked the data needed interventions. “We still didn’t have the entire picture,” says Rebecca Mann, geographic information systems data manager at International Trachoma Initiative.

The latest Esri-enhanced system is designed to correct that. Field workers collect data on smartphones and tablets. The devices quickly transfer data to a website on a server housed in Decatur where it is summarised, checked for errors, and mapped. Using a 3G connection, the data can be transmitted to the server in real time.

Next, the data moves to a central MySQL server linked to an ArcGIS mapping server. A Python script automatically converts tabulardata into feature points that link to ArcGIS map templates embedded in a project website on These points accumulate on the Web maps as data is collected, illustrating the distribution of surveyed clusters and ensuring that selected samples spatially represent the entire survey area.

The server makes the data accessible worldwide so researchers and managers can review the accumulating information in real time, and then approve it for wider dissemination such as within the trachoma atlas. The server pushes the data onto more detailed maps that show the entire survey area, providing visual displays that aid health workers in more quickly identifying areas and people needing treatment.

“Because the system is so simple, it isn’t necessary to train a specialised team,” adds Mann. When the field workers in Ethiopia started collecting data, Mann and her colleagues in Decatur could actually see it flow from the phones to their server. “Python script converted the data into feature points, which I personally added to the first mapping template,” she says. As more data came in, the system automatically updated the website.

The researchers plan to add features if the system runs smoothly. “As we get into the rhythm of things, I am sure we will want to tweak our system,” adds Mann. “But right now we are trying to keep it as simple and straightforward as possible.”

Courtesy: Esri News For Health and Human Services