Trachoma

The infection is transmitted by direct or indirect transfer of eye and nose discharges of infected people.

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%. 

Blindness may arise from repeated episodes of infection over many years.

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.

Trachoma is the leading infectious cause of blindness worldwide.

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.

Women are more often affected by trachoma than men.

Women are blinded up to 4 times as often as men, probably due to their close contact with infected children and their resulting greater frequency of infection episodes themselves.

The burden of trachoma on affected individuals and communities is enormous.

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.

 

 

Africa remains the most affected continent, and the one with the most intensive control efforts.

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 elimination strategy is summarized by the acronym "SAFE", which means Surgery for advanced disease, Antibiotics to clear C. trachomatis infection, Facial cleanliness and Environmental improvement to reduce transmission.

The WHO-recommended SAFE strategy consists of :

• Surgery to treat the blinding stage (trachomatous trichiasis);
• Antibiotics to clear infection, particularly mass drug administration of the antibiotic azithromycin, which is donated by the manufacturer to elimination programmes, through the International Trachoma Initiative;
• Facial cleanliness; and
• Environmental improvement, particularly improving access to water and sanitation.

 

Baseline surveys of trachoma are essential for planning implementation of the SAFE strategy

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.

 

 

In 1996, WHO launched the WHO Alliance for the Global Elimination of Trachoma by 2020.

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.

 

 

As of 2 January 2020, 13 countries had reported achieving elimination goals.

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.