Almost two decades of global work has drastically reduced the number of people at risk of blindness from trachoma from 1.5 billion in 2002 to under 137 million in May 2020 – a 91% decrease. Also in 2002, there were an estimated 7.6 million people with trachomatous trichiasis (TT); by May 2020, this figure had dropped by 74% to 2 million. The 2020 figures represent decreases of 4% and 20%, respectively, since the corresponding 2019 estimates.
Trachoma is a neglected tropical disease and the leading infectious cause of blindness worldwide. It is caused by repeated infection of the eye with particular strains of a bacterium.
In 2019 alone, more than 95 million people received antibiotic treatment to eliminate trachoma. About 62% of all treatment was given in Ethiopia, the country with the largest population at risk. In the same year, a total of 92 622 people were managed for TT.
As global work to eliminate the disease as a public health problem continues, driven largely by the WHO Alliance for the Global Elimination of Trachoma by 2020 (GET2020), a review of the 2020 deadline has become important in line with those for several other NTDs and the Sustainable Development Goals. The new target date for global elimination of trachoma as a public health problem is 2030. Measures envisaged in the new 2021–2030 NTD road map include a call for a strategic shift from disease-specific perspectives to a holistic approach based on universal health coverage.
“The year 2020 was meant to see an end to trachoma as a public health problem. This will not happen, but reflection on the tremendous gains made so far strengthens our determination to end this disease. Doing so will require the integrated measures envisaged in the new road map,” said Dr Mwele Ntuli Malecela, Director, WHO Department of Control of Neglected Tropical Diseases. “Progress achieved by many partners since 2002 is evident – not only have many millions of people been spared the painful loss of vision but hundreds of millions more will avoid it in the future.”
The importance of data
Continued progress against trachoma can be attributed to three factors.
“First, health ministries and their partners have made enormous efforts to implement the WHO-endorsed SAFE strategy for trachoma elimination. Second, in some areas, general socioeconomic development has probably contributed. Third, we are generating much better data. This increases our ability to deliver precision public health,” said Dr Anthony Solomon, Chief Scientist, WHO Department of Control of Neglected Tropical Diseases.
Gender-disaggregated data received by WHO show that of individuals operated for TT in 2019, 67% were female.
“The odds of women contracting trichiasis are, on average, 1.8 times higher than in men: this finding is a good indicator of gender equity in delivery of surgery,” added Dr Solomon.
Validation and the SAFE strategy
Since 2011, WHO has validated nine countries (Cambodia, China, Ghana, Islamic Republic of Iran, Lao People’s Democratic Republic, Mexico, Morocco, Nepal and Oman) as having eliminated trachoma as a public health problem. A further four countries (Gambia, Iraq, Myanmar and Togo) have reported that they have achieved the prevalence targets for elimination.
WHO recommends the SAFE (surgery for trichiasis, antibiotics to clear infection, and facial cleanliness and environmental improvement to reduce transmission) strategy to control, prevent and eliminate the disease.
In 1996, WHO launched the WHO Alliance for GET2020. With other partners in the Alliance, WHO supports country implementation of the SAFE strategy and strengthening of national capacity through epidemiological assessment, monitoring, surveillance, project evaluation and resource mobilization.
Trachoma, an eye disease caused by infection with the bacterium Chlamydia trachomatis, is spread through contact with infective eye or nose discharges. Infection is particularly common in young children.
Ocular or nasal discharge can be transmitted directly from person to person, be deposited on surfaces for later transfer into a previously uninfected eye, or be carried by flies which have been in contact with the eyes and noses of infected people.
Transmission is associated with poor sanitation and hygiene, which increase the availability of eye discharges and encourage the breeding of flies.
The antibiotic used most widely is azithromycin (Zithromax®, Pfizer, New York, NY, USA) donated to trachoma-endemic countries through the International Trachoma Initiative (www.trachoma.org).