Drug-resistant strains of TB are out of control, warn health experts

The fight against new, antibiotic-resistant strains of tuberculosis has already been lost in some parts of the world, according to a senior World Health Organisation expert. Figures show a 5% rise in the number of new cases of the highly infectious disease in the UK.

Dr Paul Nunn, head of the WHO's global TB response team, is leading the efforts against multi-drug resistant TB (MDR-TB). Nunn said that, while TB is preventable and curable, a combination of bad management and misdiagnosis was leaving pharmaceutical companies struggling to keep up. Meanwhile, the disease kills millions every year.

"It occurs basically when the health system screws up," said Nunn. "Treating TB requires a carefully followed regime of medication over six months. In places where health services are fragmented or underfunded, or patients poor and health professionals ill-trained, that treatment can fall short, which can in turn lead to patients developing drug-resistant strains. It's been estimated that an undiagnosed TB-infected person can infect 10 others a year.

"There's a vicious circle, because when new drugs come out they are expensive, so there is no demand. Without the volume of demand, the cost will not come down. If we can't tackle this, we are going to finish up with a lot more people being diagnosed with multi-drug resistant strains. We've already lost the battle in places such as the former Soviet Union, and so we need a huge expansion of effort, especially in places like India and China." He added: "In some areas we have probably already lost the battle. Globally, it is still just 5% of the total number of TB cases, but with sloppy management of treatment we are moving towards an accelerating problem."

Tuberculosis is long thought to have lost out as donors preferred to fund HIV research and healthcare for children. "The absolute numbers were seen to be falling and TB seemed somehow to lose out and never had the profile of other health issues; it was the orphan child and just didn't get the same funding," said Nunn. But while there were few drugs on the horizon, new rapid diagnostic tests were a "wonderful" breakthrough.

Anti-tuberculosis (TB) drug resistance is a major public health problem that threatens progress made in TB care and control worldwide. Drug resistance arises due to improper use of antibiotics in chemotherapy of drug-susceptible TB patients. This improper use is a result of a number of actions including, administration of improper treatment regimens and failure to ensure that patients complete the whole course of treatment. Essentially, drug resistance arises in areas with weak TB control programmes. A patient who develops active disease with a drug-resistant TB strain can transmit this form of TB to other individuals.

It is 130 years since the German scientist Dr Robert Koch astounded the world by announcing that he had discovered the cause of tuberculosis, the TB bacillus. At the time TB was raging through Europe and the Americas, killing one in seven people. Today tuberculosis remains an epidemic in much of the world, causing the deaths of several million people each year, most of them in developing countries. The combination of HIV and TB has proved catastrophic. More than 350,000 people living with HIV died because of TB in 2010.