THE BROADER PICTURE / Agony of the Zulus

FRAIL OLD Mzikane Mthethwa crawls on her hands and knees over the sand and thorns. Her face is screwed up in pain, her dull eyes stare at the ground. She can't stand or sit upright; it's only a few steps to the shade of her hut, but every movement of her deformed body is a slow, painful ordeal.

In the small, sparsely populated area of Kwa-Zulu, near the Mkuze river in South Africa, as many as 6,000 of the 15,000 residents are suffering from a mysterious disease which was first reported in the Sixties, and which attacks only one group of the population: Zulus. Mseleni Joint Disease, or MJD, is a form of arthritis which attacks its victims at random - men and women, young and old. About 65 per cent of women and 25 per cent of men in the area are affected.

For most who suffer from the condition, pain in their hips starts in their late twenties. With age, the pain spreads to the neck, back, hands, knees and feet. One sufferer, who has had the condition for the past 20 years, described it thus: "The pain was light at first, in my hips. As I got older it almost crippled me completely. Now the pain is like lightning in my body." There is no cure for the disease, and although there are theories about its origins - including the possibility that it might be tick-borne, or caused by the use of chemical sprays on crops - its cause remains unknown. Recent research suggests that MJD may be a combination of three conditions: retarded growth, or dwarfism; nutritional factors; and a kind of osteo-arthritis that destroys cartilage in the joints, causing unbearable pain. It is not hereditary.

Kwa-Zulu only measures about 13km by 18km, but its harsh, desert-like terrain is difficult - even for the able-bodied - to negotiate. Doctors estimate that as many as 2,000 local people can get around only by crawling or dragging themselves through the bush on their arms. Others struggle along the winding roads with home-made walking-sticks made from planks and branches. One way or another, though, they make their journeys: partly for such daily necessities as fetching water, but also for their weekly visit to hospital.

Every Wednesday, a stream of sufferers lines up at Mseleni Hospital, a local centre built by missionaries in the Thirties. But there is only so much that the doctors can do. Patients are given anti-inflammatory injections, which do not always work, or, in more serious cases, hip replacements. For those not able to reach the hospital, their only chance lies in being spotted by one of the four-wheel-drive ambulances which drive around the bush searching for sufferers.

One consolation Mseleni Hospital can offer is access to a disability pension for victims. The monthly sum of 350 rand (pounds 62) will buy food for a family of three, and, in an area of high unemployment, represents more than the average able-bodied labourer's wage. But although the money helps, it cannot disguise the generally catastrophic effect on the community of such widespread disability. "Although people are very stoical," says Mseleni Hospital's Dr Victor Fredlund, "the community's ability to cope with life is affected. It's difficult to find families that don't have disabled members." And, because of the rugged nature of the environment, it is not even possible to alleviate the suffering of the disabled with wheelchairs. As Dr Fredlund points out, "It would be more difficult to get around in a wheelchair than to crawl." !