Tibet in race to cure rare bone disease

TOPPYE is about 30 years old, but his body never had a chance to grow up. As a child in rural Tibet he fell victim to a mysterious disease, known locally as "Big Bone Disease", the cause of which is still unknown but it threatens millions of impoverished villagers in Tibet and parts of northern China. As a result, his upper limbs never reached half their usual length and his painful joints are so badly deformed they have as little as 30 degrees mobility.

Big Bone Disease, known medically as Kashin-Beck Disease (KBD), is a chronic degenerative ailment which destroys the growth cartilage and joint cartilage in childhood. Francoise Mathieu, a physiotherapist working in Tibet for Medecins sans Frontieres describes showing an X-ray of a Tibetan patient to doctors in Europe. "They thought I was showing an X-ray of a person 70-80 years old, not a 15 year-old."

There is no cure for the disease. As far as is known, it is only found within a crescent-shaped swathe which covers parts of Tibet, northern China, Mongolia, Siberia and North Korea. In China, 30 million people live in endemic areas, and at least two million to three million are affected, most of whom live in remote areas high on the Tibetan plateau. Fifty years of Chinese research has failed to find a cause or significantly to ameliorate the effects of KBD.

"Most of the time, it is endemic in very poor areas," said Ms Mathieu. "There is up to 90 per cent prevalence in some areas, which leads to big problems." Most of the victims are farmers who must toil the land in harsh, primitive conditions. "Most of the time they cannot finish the work. So they must pay someone else. It is a whole vicious circle."

In Tibet the disease does not affect urban residents or, interestingly, nomadic herders. MSF discovered the problem by accident. In 1991 the aid group was working on a medical and sanitation programme in Tibet. "By chance we were working in areas where KBD occurred. We had never seen it in other countries," said Ms Mathieu. Children as young as four years old were diagnosed with KBD.

MSF set up a programme for tackling the symptoms with regular physiotherapy. "Physiotherapy can help with the relief of pain, and to recover a greater range of motion of the limbs," said Ms Mathieu. In the past six years, MSF has opened 60 remote physio clinics and trained 90 Tibetan doctors.

But that still left the mystery of what was causing the affliction. KBD was first diagnosed in 1849 by Dr Kashin, a Russian doctor who settled near Lake Baikal in Siberia. A few years later, another Russian, Dr Beck, identified it among Kazakhs.

In Tibet, the risk factors seem to be selenium deficiency in the soil, fungal contamination of barley (the staple grain) and organic matter in the water. The thesis is that the disease is a result of mycotoxins, produced by the fungi, which act on the body. But it is still a puzzle how the three risk factors interact with each other with this tragic result.

A symposium has just taken place in Peking to raise international awareness. In collaboration with European research- ers, MSF has set up a three- year project in 22 Tibetan villages, where the infection rate ranged from 45 to 97 per cent: 1,000 children aged between five and 15 are covered by the study to try to establish how the disease develops.

Camille Chasseur, at the Louis Pasteur Institute of Public Health in Brussels, said: "We've only got a hypothesis. We don't know where the contamination begins, in the field, during harvest or in the storeroom."

The preventive programme is tackling all the risk factors, by distributing selenium supplements, providing clean drinking water, and encouraging the Tibetans to dry their grain properly and use fungicide.

But, even if the results are positive, it will be a long time before Big Bone Disease becomes a thing of the past. "It will take 10 years minimum to see a decline," Ms Mathieu admitted.