Drug resistant tuberculosis is spreading faster than previously feared and its rate of occurrence is at an all-time high, a new report by the World Health Organisation has found.
The study, 'Anti-tuberculosis drug resistance in the world', is based on data collected between 2002 and 2006 on 90,000 TB patients in 81 countries. It found that extensively drug-resistant tuberculosis (XDR-TB), a virtually untreatable form of the respiratory disease, has been recorded in 45 countries.
The agency estimates that nearly half a million new cases of multi-drug-resistant TB, known as MDR-TB, are detected annually worldwide, accounting for 5 per cent of the 9 million new cases every year.
"TB drug assistance needs a frontal assault," says Mario Raviglione, Director of WHO's Stop TB Department.
The highest rate of MDR-TB was found in Azerbaijan's capital Baku, where nearly one quarter of all new TB cases were reported to be multi-drug-resistant. This type of TB is also widespread in Moldova, Ukraine, Russia, Uzbekistan and China.
The report also spotted ties between HIV infection and MDR-TB, with surveys in Latvia and Donetsk, Ukraine revealing that the rate of MDR-TB is twice as high among tuberculosis patients living with HIV than those without the disease.
The agency reported notable successes, such as Estonia and Latvia, which were deemed MDR-TB 'hotspots' more than a dozen years ago but whose rates are now stabilising.
However, given that only six countries in Africa -- the continent with the highest incidence of TB globally -- were able to submit data for the report, WHO pointed out that the magnitude of the respiratory disease in some parts of the world remains unknown.
"It is likely there are outbreaks of drug resistance going unnoticed and undetected," says WHO tuberculosis expert Abigail Wright, the report's principal author.
WHO estimates that $4.8 billion is needed for overall TB control in low- and middle-income countries in 2008, with $1 billion for MDR-TB and XDR-TB. But there is a total finance gap of $2.5 billion, including a $500 million gap for MDR-TB and XDR-TB.
"The threat created by TB drug resistance demands that we fill these gaps, as laid out in the Global Plan to Stop TB, a roadmap for halving TB prevalence and deaths compared with 1990 levels by 2015," said Dr Marcos Espinal, Executive Secretary of the Stop TB Partnership.
