A new survey by the World Health Organization (WHO) has found the highest rates ever recorded for multidrug-resistant tuberculosis (MDR-TB) globally are occurring today. This is the largest survey on drug resistant TB ever to be conducted, the data for which was collected between 2002 and 2006.
The survey, published Monday 26th February and titled Anti-tuberculosis drug resistance in the world, covers 90,000 TB patients in 81 countries and also found that 45 countries have recorded cases of extensively drug-resistant tuberculosis ((XDR-TB). This is the first time the WHO survey has covered this virtually untreatable form of TB, and because many countries are not equipped to diagnose it, the real picture could be worse.
TB is an infectious airborne respiratory disease caused by a bacteria that is spread by the coughing of infected people. Despite the disease being preventable and curable, 8.8 million people caught it and 1.6 million died in 2005.
If detected early and treated completely, a person with TB can quickly become non-infectious and will eventually be completely cured. However, the bacteria has evolved into numerous drug resistant forms, a scenario that presents public health authorities with major challenges in the campaign to eradicate the disease.
Director of the WHO Stop TB Department, Dr Mario Raviglione, said:
“TB drug resistance needs a frontal assault. If countries and the international community fail to address it aggressively now we will lose this battle.”
He added that, as well as confronting resistant forms of TB and saving lives:
“Programmes worldwide 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.”
There are nearly half a million new cases of MDR-TB globally a year, the WHO estimates from the new survey data. This represents about 5 per cent of all new 9 million TB infections.
The highest incidence of MDR-TB was found in Baku, the capital of Azerbaijan, which lies between Eastern Europe and Western Asia. Here the survey found nearly a quarter of new cases of TB were of the multidrug resistant type.
Other Eastern European and Asian countries were next in line: Moldova (19.4 per cent), Donetsk in the Ukraine (16 per cent), Tomsk Oblast in the Russian Federation (15 per cent), and Tashkent in Uzbekistan (14.8 per cent). These rates exceed the highest levels of drug resistant TB published in the 2004 WHO report.
According to the WHO, there are comparable rates of widespread MDR-TB in China.
The new survey also found a significant association between HIV infection and MDR-TB, typified by the situation in Latvia and the Ukraine where MDR-TB is nearly twice as common in patients with HIV as in TB patients without HIV.
However, all is not doom and gloom and the new report also highlights successes. Estonia and Latvia, two Baltic countries that 13 years ago were classed as drug-resistant TB hotspots, are said to be showing signs of stabilizing, with notification of new TB cases falling. This follows a substantial injection of funds to support a campaign against MDR-TB.
The survey included data on drug resistant forms of TB from only six African countries, not enough to reveal the extent of the problem in a part of the world with the highest overall incidence of TB.
According to the WHO, it is virtually impossible to get data on drug resistant TB in Africa because of lack of the right equipment and staff trained to spot the drug resistant forms of the disease.
Principal author of the report, and TB expert with the WHO, Abigail Wright, said:
“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,” she added.
Nearly 5 billion dollars is needed to establish overall control of TB in low and middle income countries in 2008, estimates the WHO. 1 billion of this is needed for MDR-TB and XDR-TB. But all the money is not yet forthcoming: there is a shortfall of 2.5 billion, which includes a half billion gap for MDR-TB and XDR-TB.
Executive Secretary of the Stop TB Partnership, Dr Marcos Espinal pointed to the seriousness of this shortfall:
“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.”
Click here for the Global Plan to Stop TB.
Sources: World Health Organization (WHO).
Written by: Catharine Paddock, PhD