Trachoma is the world’s leading infectious cause of blindness and one of 18 neglected tropical diseases that affect over 1 billion of the world’s poorest people. It is caused by the bacterium chlamydia trachomatis.
The bacteria are spread through contact with eye discharge from an infected person – via hands, towels, sheets and, in some cases, eye-seeking flies, and thrive where there is poor sanitation and limited access to water for personal hygiene.
Repeated infection damages the eyelids in some individuals so that the normal defences are compromised causing the eyelashes turn inwards and rub painfully against the eyeball surface. This advanced stage of the disease, trachomatous trichiasis, is extremely painful and has a profoundly negative impact on an individual’s quality of life. Trichiasis can be corrected by eyelid surgery, however if left untreated it may lead to irreversible low vision and blindness.
Trachoma is currently estimated to be responsible for the visual impairment of about 2.2 million people, of whom 1.2 million are irreversibly blind, with approximately 232 million people worldwide living in trachoma-endemic districts. Trachoma can destroy the economic well-being of entire communities, keeping affected families trapped in a cycle of poverty as the disease passes from one generation to the next.
Globally, trachoma results in an estimated US $2.9 billion in lost productivity per year. Total loss of productivity for the visually impaired or blind and their caregivers has been estimated at $3bn-$6bn annually .
While children are the most susceptible to infection, the blinding effects of repeated infection do not usually develop until adulthood. In most communities, women are about twice as likely as men to develop trichiasis, in part because of repeated exposure to their children's infections. The disabling effects of vision loss further compounds other common challenges faced by poor and marginalised people.
In 1998, the World Health Organization (WHO) Alliance for the Global Elimination of Trachoma by 2020 (GET 2020 Alliance) was created to address this health and development burden. The GET2020 Alliance is the principal platform through which the trachoma prevention community works together towards a shared goal. It includes representatives from 51 endemic country governments as well as other non-government development organizations (NDGOs), academic institutions, and donor and private sector stakeholders.
Adding further support to the Alliance, in May 1998, the 51st World Health Assembly adopted a resolution calling for the elimination of trachoma as a cause of blindness and recommending that Ministries of Health pursue the SAFE strategy to do so (WHA Resolution 51.11). WHO recommends that elimination of trachoma as a public health problem is approached through the SAFE strategy, which consists of surgery (S), antibiotics (A), facial cleanliness (F) and environmental improvement (E) interventions.
This approach includes reducing the prevalence of active disease in a population as well as undertaking corrective surgery on people suffering from the blinding stage of the disease. The delivery of this comprehensive approach is critical for the sustainability of trachoma elimination, which may be particularly contingent on the facial cleanliness and environmental improvement components. Importantly, trachoma interventions are undertaken within national health systems and integrated into national priorities, contributing to health system strengthening through the building of knowledge, skills and capacity.
For more information about the story of trachoma, read Katherine Schlosser's article on the history of trachoma.