Academic Reading — Test 177

Reading passage

Trachoma is an infectious disease of the eye and the leading infectious cause of blindness in the world. It is caused by a bacterium called Chlamydia trachomatis, which spreads from person to person through contact with the discharge from the eyes and noses of infected people. Flies that have touched such discharge can also carry the bacterium between individuals, and shared items such as towels and bedding provide another route of transmission. The disease is most common in poor rural communities where access to clean water and basic sanitation is limited. For this reason, although trachoma was once widespread across Europe and North America, it has gradually disappeared from wealthier regions and now persists chiefly in parts of Africa, the Middle East and Asia. Africa carries the heaviest burden, accounting for the majority of people who remain at risk today. The progression of the disease is slow and often invisible in its early stages. A single infection in childhood produces inflammation on the inner surface of the upper eyelid, but this usually heals without lasting harm. The danger lies in repeated infection over many years. Each new episode leaves a small amount of scarring, and as the scars accumulate the eyelid begins to contract and turn inwards. Eventually the eyelashes are dragged into a position where they rub against the surface of the eye with every blink. This painful condition, known as trichiasis, slowly damages the cornea, the transparent layer at the front of the eye. Without treatment the cornea becomes cloudy, and the loss of sight that follows is irreversible. Because the damage builds up over decades, blindness from trachoma typically appears in adulthood, by which time the underlying cause may be long forgotten. The disease does not affect everyone equally. Women are blinded by trachoma far more often than men, a pattern that researchers attribute mainly to their close and frequent contact with young children, who are the principal reservoir of infection. Mothers and grandmothers who care for infected children are repeatedly exposed, and so the cycle of reinfection is hardest to break within the household. The economic consequences are considerable. A person who loses their sight in their working years can no longer farm, trade or care for a family, and the community must support them rather than benefit from their labour. In this way trachoma both arises from poverty and deepens it. The international response to the disease is built around a strategy promoted by the World Health Organization and known by the abbreviation SAFE. Each letter stands for one part of a combined approach. The "S" refers to surgery to correct eyelids that have already turned inwards, a relatively simple operation that can be performed by trained health workers close to where patients live. The "A" stands for antibiotics, principally a drug called azithromycin, which is distributed to whole communities to reduce the pool of infection. The "F" represents facial cleanliness, since regularly washing children's faces removes the discharge that attracts flies and carries the bacterium. The final letter, "E", stands for environmental improvement, above all the provision of clean water and proper latrines, which tackles the root conditions in which trachoma thrives. The strategy is deliberately broad because medicine alone cannot succeed where the surrounding circumstances continue to spread the disease. Putting this strategy into practice across a continent has demanded an unusual degree of cooperation. National health ministries, charities, donors and pharmaceutical companies have worked together on a scale rarely seen in global health. The manufacturer of azithromycin agreed to donate the medicine free of charge, and hundreds of millions of doses have since been delivered. Mapping the disease was itself an enormous task: before treatment could be planned, teams had to travel to remote districts and examine the eyes of local people to establish where trachoma was present and how severe it had become. This survey, one of the largest of its kind ever undertaken, allowed resources to be directed precisely to the places that needed them most. The results have been encouraging, though the work is far from finished. Several African nations have now been formally validated as having eliminated trachoma as a public health problem, meaning that the disease no longer causes blindness at a significant rate within their borders. Millions of people who would once have gone blind have kept their sight. Yet pockets of infection remain, and there is always a risk that the disease will return if clean water and good hygiene are not sustained. Trachoma is, after all, a condition of poverty, and lasting victory depends as much on development as on medicine. The campaign has shown that an ancient disease can be pushed back by patient, coordinated effort, but it has also shown that the final steps are often the hardest.