Many vulnerable groups are at risk of contracting TB

The World Health Organization has warned that about one in three of the 42 million people living with the Aids virus also have TB and 90% of them will die within a few months without the right treatment.

Ten years ago, the WHO declared that TB represented a "global emergency", but the epidemic has grown "ever worse", acting director Mario Raviglione told reporters.

"We need to increase our efforts to address the deadly synergy between the two diseases, each of which is fuelling the other's impact," he said.

Effective drugs are available to treat TB and they are comparatively cheap at around $10 per patient.

'Scandal'

But they need to be taken for six months in order to cure the disease.

Dr Raviglione said this often does not happen.

"It is a scandal that today in the world we have so many cases that cannot finish their treatment when we have a treatment available that is highly effective and that cures basically 95-98% of all cases."

In Africa, the WHO says, fewer than one patient in three receives a full course of drugs; in Russia, the figure is even lower.

It is no coincidence that in both regions the number of TB cases is rising dramatically - by 6% a year in Africa, and even more in Russia.

Short of funds

Without HIV, Dr Raviglione says, there would be virtually no tuberculosis in Africa.

However, the worst-affected country is India, with almost two million new cases annually, fuelled by poverty and the rising rate of HIV infections.

The WHO says that Western donor nations must make the drugs available free and establish ways of distributing them effectively.

If not, tuberculosis will at some point become a problem in the West as well.

In a report released at the International Aids Society conference in Paris, the WHO said it was short of $3.8bn for a $9.1bn five-year plan to halt the spread of tuberculosis by 2005.

The report is published a day before a donors' meeting on the Global Fund to Fight AIDS, TB and Malaria.