100 Million Worldwide at Risk for Blindness from Trachoma

By Lila Abassi — Mar 15, 2016
The Global Trachoma Mapping Project is the largest ever project undertaken to track the prevalence of trachoma, the most common infectious cause of blindness globally. The effort revealed that 100 million people around the world are at risk of going blind.
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The Global Trachoma Mapping Project, arguably one of the most ambitious public health projects since the eradication of smallpox, was the largest-scale study of an infectious disease to have ever taken place. Its disturbing conclusions is that 100 million people are at risk of blindness due to trachoma.

Most of us probably have no idea what trachoma is, but this disease, which is caused by Chlamydia trachomatis, is the leading infectious cause of blindness worldwide, affecting about 2.2 million people, 1.2 million of whom will suffer irreversible loss of sight. There are many serotypes of C. trachomatis; some cause genital infections, and some cause trachoma.

Transmission of the infection occurs by close social or sexual contact. Active infections are most commonly seen in young children, with a peak incidence around age four to six years. Scarring and blindness is more commonly seen in adults. Women have six times the rate of infection than men, which is likely a result of continuous exposure to children who are infected.

The sad reality is that with the availability of cheap antibiotics and minimal health care, the disease could be easily prevented or cured, and possibly even eradicated.

The effort, was spearheaded by Sightsavers, a charity based in the United Kingdom and funded by the UK government’s Department of International Development (DFID), with funding also provided by USAID. The three-year study, which took place between December 2012 and January 2015, involved data collection on 2.6 million individuals in 29 countries across the globe, using mobile devices for data gathering. The project staff was able to gather data from the most remote regions of these countries to accurately identify where the world’s trachoma endemic areas are.

Thus far, one of the greatest obstacles in treating trachoma has been determining where the disease is causing the most suffering. Trachoma is endemic to 50 countries, and mostly confined to poverty-stricken regions in Africa, the Middle East, Asia, Latin America, Pacific Islands, and remote Aboriginal communities in Australia.

Using a sample of the individuals who were representative of 224 million people, the project staff successfully mapped areas of the world that were affected by the disease, but no data existed, because of the remoteness of the area, lack of security, lack of funding, or other public health concerns that were of greater concern.

The three-year effort included more than 550 teams of trained surveyors, including ophthalmic nurses, in nations such as Chad, Eritrea, Pakistan, Papua New Guinea, Solomon Islands, Colombia and Yemen. Data were gathered on total of 2,500 people around the world.

As per the World Health Organization guidelines, any population where the prevalence of trachoma among children nine years of age or younger is greater than 10 percent, warrants mass treatment with antibiotics of all members of the community. Other measures to help treat the disease are part of what is referred to as the SAFE strategy, which includes interventions such as surgery, antibiotics, facial cleanliness and environmental improvements (especially improved sanitation). The WHO hopes to eradicate trachoma as a cause of blindness by the year 2020, utilizing the SAFE strategy is its core tool.

Sarah Bartlett, a Sightsavers health advisor for neglected tropical diseases, feels that this method of data gathering will provide the basis for providing interventions and potentially eliminating other neglected tropical diseases which would prove invaluable not only on a humanitarian level but potentially save governments billions of dollars.