Trachoma is a disease of the eye and the leading infectious cause of blindness worldwide. It is caused by an obligate intracellular bacterium called Chlamydia trachomatis. Infection is transmitted among people by direct or indirect transfer of ocular and nasal discharges of infected people; indirect transfer includes carriage on the body of particular species of flies.
These discharges can be spread by particular species of flies.Young children harbour the principal reservoir of infection. In areas where trachoma is endemic, active (inflammatory) trachoma is common among preschool-aged children, with prevalence rates which can be as high as 60–90%.
An individual’s immune system can clear a single episode of infection, but in endemic communities, re-acquisition of the organism occurs frequently.
With repeated episodes of infection over many years, the eyelashes may be drawn in so that they rub on the surface of the eye, with pain and discomfort and permanent damage to the cornea. Left untreated, this condition leads to the formation of irreversible opacities, with resulting visual impairment or blindness.
It is a public health problem in 44 countries, and is responsible for the blindness or visual impairment of about 1.9 million people.
Blindness from trachoma is irreversible.
Visual impairment or blindness results in a worsening of the life experience of affected individuals and their families, who are normally already amongst the poorest of the poor.
The economic cost in terms of lost productivity from blindness and visual impairment is estimated at US$ 2.9–5.3 billion annually, increasing to US$ 8 billion when trichiasis is included.
Trachoma is hyperendemic in many of the poorest and most rural areas of 37 countries of Africa, Central and South America, Asia, Australia and the Middle East.
The WHO-recommended SAFE strategy consists of :
WHO has also created and fostered Tropical Data, a collaboration with the International Trachoma Initiative at the Task Force for Global Health; the London School of Hygiene & Tropical Medicine; RTI International; and Sightsavers, which supports national programmes to generate high-quality prevalence data by providing epidemiological, training, logistical and data management support for all types of cross-sectional surveys on trachoma. WHO provides oversight on survey protocols and ensures that country interests are maintained.
The Alliance is a partnership which supports implementation of the SAFE strategy by Member States, and the strengthening of national capacity through epidemiological surveys, monitoring, surveillance, project evaluation, and resource mobilization.
These countries are: Cambodia, China, Gambia, Ghana, Islamic Republic of Iran, Iraq, Lao People’s Democratic Republic, Mexico, Morocco, Myanmar, Nepal, Oman and Togo. Eight of those countries – Cambodia, Islamic Republic of Iran, Lao People’s Democratic Republic, Ghana, Mexico, Morocco, Nepal and Oman – had been validated by WHO as having eliminated trachoma as a public health problem.