Tuberculosis (TB)

World health organization reports highest rates of drug-resistant tuberculosis to date

In Tomsk, Russian Federation, a TB out-patient, signs a register after taking his medication in front of his home
The Global Fund/Oliver O’Hanlon

26 February 2008 -- Washington DC / Geneva - Multidrug-resistant tuberculosis (MDR-TB) has been recorded at the highest rates ever, according to a new World Health Organization (WHO) report that presents findings from the largest survey to date on the scale of drug resistance in tuberculosis.

The report, Anti-Tuberculosis Drug Resistance in the World, is based on information collected between 2002 and 2006 on 90 000 TB patients in 81 countries. It also found that extensively drug-resistant tuberculosis (XDR-TB), a virtually untreatable form of the respiratory disease, has been recorded in 45 countries.

MDR-TB patient receiving IV treatment in a hospital in Latvia
WHO/G. Thomas

The report also found a link between HIV infection and MDR-TB. Surveys in Latvia and Donetsk, Ukraine found nearly twice the level of MDR-TB among TB patients living with HIV compared with TB patients without HIV.

Based on analysis of the survey data, WHO estimates there are nearly half a million new cases of MDR-TB--about 5% of the total nine million new TB cases--worldwide each year. The highest rate was recorded in Baku, the capital of Azerbaijan, where nearly a quarter of all new TB cases (22.3%) were reported as multidrug-resistant. Proportions of MDR-TB among new TB cases were 19.4% in Moldova, 16% in Donetsk in Ukraine, 15% in Tomsk Oblast in the Russian Federation and 14.8% in Tashkent in Uzbekistan. These rates surpass the highest levels of drug resistance published in the last WHO report in 2004. Surveys in China also suggest that MDR-TB is widespread in that country.

"TB drug resistance needs a frontal assault. If countries and the international community fail to address it aggressively now we will lose this battle," said Dr Mario Raviglione, Director of the WHO Stop TB Department. "In addition to specifically confronting drug-resistant TB and saving lives, programmes world-wide must immediately improve their performance in diagnosing all TB cases rapidly and treating them until cured, which is the best way to prevent the development of drug resistance."

For the first time, the global survey includes analysis of XDR-TB. However, because few countries are equipped at present to diagnose it, limited data were available for this report.

Although the report highlights the extent of drug resistance, it also points to some successes. Thirteen years ago, Estonia and Latvia were singled out by WHO as drug-resistant TB "hotspots". Today, following a substantial investment and a sustained assault on MDR-TB, rates in these two Baltic countries are stabilizing and TB case notification rates are falling.

The true scale of the problem also remains unknown in some pockets of the world. Only six countries in Africa—the region with the highest incidence of TB in the world***--were able to provide drug resistance data for the report. Other countries in the region could not conduct surveys because they lack the equipment and trained personnel needed to identify drug-resistant TB. "Without these data, it is difficult to estimate the true burden and trends of MDR-TB and XDR-TB in the region. It is likely there are outbreaks of drug resistance going unnoticed and undetected," said WHO TB expert Abigail Wright, the principal author of the report.

WHO estimates that US$4.8 billion is needed for overall TB control in low- and middle-income countries in 2008, with US$1 billion for MDR-TB and XDR-TB. But there is a total financing gap of $2.5 billion, including a US$ 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. "The Plan also calls for another imperative--sufficient resources for research to find new diagnostics, new drugs effective against resistant strains and an effective TB vaccine."

NOTE TO EDITORS:

* The bacteria responsible for TB become resistant when people ill with TB are not provided with or do not complete a full course of medication. Drug-resistant TB, like drug-sensitive TB, can also be transmitted through the air from an infected person to a non-infected person. MDR-TB is a form of TB that does not respond to the standard six month treatment using first line-drugs (i.e. resistant to isoniazid and rifampicin). It can take two years to treat with drugs that are 100 times more expensive than first-line treatment.

** XDR-TB is a form of TB caused by bacteria resistant to virtually all the most effective anti-TB drugs (i.e. MDR-TB plus resistance to any fluoroquinolones and any one of the second-line anti-TB injectable drugs: amikacin, kanamycin or capreomycin).

*** In sub-Saharan Africa HIV/AIDS is dramatically fuelling the spread of TB. TB is a major cause of death among people living with HIV. MDR-TB and XDR-TB are highly lethal in people living with HIV -- studies show case fatality rates of over 90%. Drug-resistant TB is therefore a major threat to the effectiveness of both TB treatment and anti-retroviral treatment programs.


For copies of the report, or for more information, please contact:

Glenn Thomas, WHO Stop TB Department. Tel: +41 795090677. E-mail: thomasg@who.int

Judith Mandelbaum-Schmid, Stop TB Partnership. Tel: +41 792546835. E-mail: schmidj@who.int

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