Trachoma

Trachoma is the leading infectious cause of blindness worldwide. It is caused by an obligate intracellular bacterium called Chlamydia trachomatis. The infection is transmitted by direct or indirect transfer of eye and nose discharges of infected people, particularly young children who harbour the principal reservoir of infection. These discharges can be spread by particular species of flies. 

WHO estimates suggest that 150 million people worldwide are affected by Trachoma and 6 million of them are blind or at risk of visually disabling complications. Trachoma is found in underprivileged communities living in poor environmental conditions.

Epidemiology and clinical features

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%. Infection becomes less frequent and shorter in duration with increasing age. Infection is usually acquired when living in close proximity to others with active disease, and the family is the main setting for transmission. An individual’s immune system can clear a single episode of infection, but in endemic communities re-acquisition of the organism occurs frequently. 

After years of repeated infection, the inside of the eyelid can become so severely scarred (trachomatous conjunctival scarring) that it turns inwards and causes the eyelashes to rub against the eyeball (trachomatous trichiasis), resulting in constant pain and light intolerance. This and other alterations of the eye can lead to scarring of the cornea. Left untreated, this condition leads to the formation of irreversible opacities, with resulting visual impairment or blindness. The age at which this occurs depends on several factors including local transmission intensity. In very highly endemic communities it can occur in childhood, though onset of visual impairment between the ages of 30 and 40 years is more typical. 

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. 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. 

Environmental factors associated with more intense transmission of C. trachomatis include:

• inadequate hygiene
• crowded households
• inadequate access to water
• inadequate access to and use of sanitation.

Prevention and control

Elimination programmes in endemic countries are being implemented using the WHO-recommended SAFE strategy. This 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. 

Elimination of Trachoma

The World Health Assembly adopted resolution in 1998, targeting the global elimination of trachoma as a public health problem with 2020 as the target date. The neglected tropical diseases road map 2021–2030, endorsed by the World Health Assembly in 2020 through its decision sets 2030 as the new target date for global elimination.

Elimination of trachoma as a public health problem is defined as:

• a prevalence of trachomatous trichiasis “unknown to the health system” of <0.2% in adults aged ≥15 years (approximately 1 case per 1000 total population), and
• a prevalence of trachomatous inflammation – follicular in children aged 1–9 years of <5%, sustained for at least two years in the absence of ongoing antibiotic mass treatment, in each formerly endemic district; plus
• the existence of a system able to identify and manage incident trachomatous trichiasis cases, using defined strategies, with evidence of appropriate financial resources to implement those strategies.

Source : WHO

WHO declares that India has eliminated Trachoma as a public health problem in 2024

The National Trachomatous Trichiasis (TT only) Survey was carried out in 200 endemic districts of the country under National Programme for Control of Blindness & Visual Impairment (NPCBVI) from 2021-24, which was a mandate set by WHO in order to declare that India has eliminated Trachoma as a public health problem.

All the reports were compiled in a specific dossier format by the NPCBVI team and were shared with the WHO country office for final scrutiny. Finally, after years of fighting against Trachoma, WHO declared that India has eliminated Trachoma as a public health problem in 2024.