Patients with drug-resistant TB in South Africa are being systematically discharged into the community when their treatment fails, where they continue to spread the disease, doctors warn. The situation in South Africa, which does not have the advanced treatments that gives people the best chance of survival, is dire and a warning of the threat this form of tuberculosis poses to the world, say experts.

Professor Keertan Dheda of the department of medicine in Cape Town, leader of a new study published in the Lancet, said that research into new drugs to treat drug-resistant TB was urgently needed and that modern versions of the old sanatoriums should be introduced, to offer voluntary seclusion and care to patients.

"In the old days there were no TB drugs too, so they shipped you off to sanatoria where you had plenty of fresh vegetables and sunlight," he said.

Patients who are untreatable but infectious and may live for a year or more are currently discharged from hospital in South Africa because there are no beds, he said. Modern-day sanatoriums would offer long-term care and physiotherapy but also activities and support for those chronically ill but still active and in danger of infecting others.

The Lancet paper investigates what happened to some of the patients in a cluster of extremely drug-resistant (XDR) TB cases in Tugela Ferry, KwaZulu-Natal province, identified in 2005-06.

More than 500 cases were diagnosed. Of those, Dheda and colleagues followed up 107. They found that despite intensive treatment with an average of eight different drugs, three-quarters (74%) of them were dead five years later. One patient had TB that was resistant to all 10 drugs that were tried. Just 12 patients (11% of the total) had good outcomes.

But the most worrying finding, the authors say, is that just under half (42%) of the patients who were sent home from hospital still had transmissible drug-resistant TB, which they would be likely to pass to their families. Tests showed that had indeed happened. "In many cases they came from very disadvantaged backgrounds," said Dheda. "Their homes were one single informal room shared by children and adults. Is it sensible to send people back to this environment and not expect the disease to spread?"

A co-ordinated global strategy to prevent the spread of disease from patients who cannot be cared for over one or more years in hospital was needed, Dheda said. Multidrug-resistant (MDR) TB is now found all over the world. What was happening in South Africa would also be happening in eastern Europe and other parts of the world, where drug-resistant TB is also growing fast.

In a linked commentary, Max O'Donnell, from the Albert Einstein College of Medicine and Neil Schluger, from Columbia University College of Physicians and Surgeons, both in New York, USA, warned that the study sounded "an urgent alarm" for global TB control.

"MDR disease in all its forms is an out-of-control problem with potentially vast and devastating repercussions for global public health," they say.

"Drug-resistant tuberculosis is an acute global health crisis. National control programmes must urgently develop strategies to use existing public health instruments for control of tuberculosis in all its forms.

"Major new investments in drug development, diagnostics, and operational research are needed. Unfortunately, as a report from Treatment Action Group indicates, global tuberculosis research budgets are shrinking, not growing. The situation regarding MDR and XDR tuberculosis is bleak."