London School of Hygiene & Tropical Medicine

An online global atlas is being launched today to show the distribution and prevalence of trachoma, the world's leading cause of infectious blindness.

The Trachoma Atlas, at http://www.trachomaatlas.org shows 49 country maps with population-based data on trachoma. The open-access, global resource is intended for public health professionals and managers of trachoma-control programs as well as the general public interested in learning about this infectious eye disease and the possible global elimination of blinding trachoma by 2020.

Mapping and assessing the magnitude of blinding trachoma is critical to defining which areas are priority for implementation of control efforts, how to monitor changes, and how to advocate for prevention and treatment.

Trachoma is estimated to be endemic in 57 countries and is responsible for 1.3 million cases of blindness worldwide. An estimated 41 million people, mostly women and children in poorer countries, have active trachoma. Repeated trachoma infections of the upper eyelid lead to scarring and inturned eyelashes, which rub on the cornea, a condition called trichiasis. Trichiasis can lead to corneal opacity and eventually blindness. Trachoma can be prevented and treated, and blinding trachoma can be eliminated as a public health threat through the WHO-endorsed SAFE Strategy-an innovative public health approach that combines trachoma treatment (Surgery and Antibiotics) with prevention (Facial-cleanliness and Environmental improvement).

The Trachoma Atlas was created by several partners, including the London School of Hygiene & Tropical Medicine, the International Trachoma Initiative at The Task Force for Global Health, Atlanta, GA, and The Carter Center, Atlanta, GA, with funding from the Bill & Melinda Gates Foundation. Data came from Ministries of Health and academic research in various countries.

Dr Danny Haddad, director of the International Trachoma Initiative, announced the launch of the Trachoma Atlas today at a Carter Center meeting of trachoma-control program managers. "We need reliable maps to achieve global elimination of blinding trachoma," he said. "The Trachoma Atlas is a terrific tool with the latest, accurate global information on trachoma in one place that everyone can use. This open-access website carries prevalence survey data, rapid assessment data, and assessments from each country's national trachoma program so one can know where trachoma is endemic or not and where treatment is needed most."

Dr Simon Brooker from the London School of Hygiene and Tropical Medicine, UK said, "The Trachoma Atlas capitalizes on the tremendous efforts of national control programs and trachoma researchers to collect survey data, very often in tough field conditions. The collation of these data into a single resource provides a powerful tool to address future scientific challenges in trachoma control, not least how to assess and verify elimination."

Mr BB Thapa, Program Director from the National Trachoma Program in Nepal said, "The Atlas will be very useful to those of us managing trachoma control programs. By providing the latest information on the magnitude of the disease burden, students, planners, researchers, donors, implementers, and evaluators can know and learn the details on trachoma prevalence in different countries in specific geographical areas."

The data at www.trachomaatlas.org include:

• Prevalence estimates of active trachoma and trichiasis from population-based prevalence surveys (PBPS)
• Maps of district level data from PBPS and trachoma rapid assessment (TRA)

The country maps are expected to be used as:

• An information resource for all partners to highlight where additional surveys are needed and the current distribution of trachoma
• An advocacy tool to prompt political will and further support for implementation efforts
• A source of data for use in operational research.

Blindness from Trachoma
Trachoma is the leading cause of preventable blindness. Trachoma originates from an eye infection that can be spread from person to person. It is frequently passed from child to child and from child to mother within the family, especially in environmental conditions of water shortages, flies, and crowded households. Through the discharge from an infected person's eyes, trachoma is passed on by hands, on clothing, or by flies that land on the person's face. Infections often begin during infancy or childhood and become chronic.

Left untreated, these infections can cause the eyelid to turn inward which causes the eyelashes to rub on the cornea, resulting in intense pain. This condition, called trichiasis, can ultimately lead to irreversible blindness, typically beginning in adulthood and often resulting in deepening poverty for individuals and their families.

Women are twice as likely as men to have trichiasis*, probably due to their close contact with infected children, and are therefore most in need of surgical services, access to antibiotics, education, and environmental improvements such as water and sanitation.

* Cromwell et al: Transactions of the Royal Society of Tropical Medicine and Hygiene, 10.1016/j.trstmh.2009.03.01