Extensively Drug-Resistant Tuberculosis (XDR-TB)
The WHO just released its 2010 report on multidrug and extensively drug-resistant tuberculosis (M/XDR-TB) surveillance and response, providing the latest information on the status of this global epidemic.
The alarming news from this report is that in some areas of the world, one in four people who were infected with tuberculosis became ill with a form of the disease that can no longer be treated with standard drug regimens. A region in Russia reported that 28% of those diagnosed with TB had the multidrug-resistant form – the highest level ever reported to WHO.
As background, multidrug-resistant tuberculosis (MDR-TB) is difficult and expensive to treat, frequently failing to respond to standard first-line drugs. Extensively drug-resistant tuberculosis (XDR-TB) is a deadlier strain, resistant to even more of the existing tuberculosis treatment.
Of the estimated 9.4 million new TB cases in 2008, approximately 440,000 were MDR-TB, and a third of those infected with this form died. It is estimated that 69,000 cases of MDR-TB occurred in Africa, with the vast majority going undiagnosed due partly to limited labratory capacity. There are no official estimated on the number of XDR-TB cases, but the WHO still suggests it may be around 25,000 annually with most cases being fatal. 58 countries have reported at least one case of XDR-TB since 2006.
Strong tuberculosis programs can have a significant impact on reducing MDR-TB rates, as seen in countries like Estonia, Latvia, the U.S. and China, Hong Kong Special Administrative Region. Additionally, new technologies that can cut the diagnosis time to two days from up to four months, offer hope in the fight against TB.
As we observe World TB Day 2010, it’s important to reflect on the progress being made in combating this disease (36 million people have been cured of tuberculosis in the last fifteen years), while acknowledging the challenges that remain, particularly in the growing area of drug resistance.
You can download the full report here.
The 2009 WHO Global Tuberculosis Update was launched earlier this month, providing the latest information on the state of the epidemic around the world. The report shows that in the last 15 years, 36 million people have been cured of tuberculosis, and eight million cases have been prevented. This progress attests to the effectiveness of the Stop TB Strategy and DOTS in the fight against tuberculosis.
During the latest 12-month reporting period, 2.3 million infectious patients were cured, more than ever before in that time frame. Still, not enough people are accessing the treatment they need, and about 1.8 million people died of tuberculosis in 2008.
There were an estimated 9.27 million incident cases of TB in 2007 (of which, 15% percent were among individuals who were also HIV-positive), a slight increase from 9.24 million in 2006. However, while the total number of TB cases is up due to population growth, the number of cases per capita is actually down 1%.
The report shows further progress in addressing the deadly combination of TB and HIV. TB remains the leading cause of death for those with HIV, but testing TB patients for HIV is on the rise, and more patients are receiving appropriate treatment.
The report also notes that there has been little progress in stopping multi-drug resistant tuberculosis (MDR-TB) and extensively drug-resistant TB (XDR-TB), an even more dangerous and resistant to treatment form of TB.
To learn more, you can read the full report, as well as the WHO’s press release.
(Alexandra Fullem works for the Global Health Council)
Yesterday the Global Health Council, Aeras Global TB Vaccine Foundation and the American Thoracic Society hosted a Congressional briefing in honor of World TB Day 2008. We learned from our 3 speakers more about the threat of MDR and XDR TB, more about the perfect storm of TB/HIV co-infection and about the great work that is being done in the push to find a vaccine. The speakers were Dr. Payam Nahid from the University of California, San Francisco, Thomas Kenyon from the Office of the Global AIDS Coordinator and Sylvie Kwedie from the Aeras Global TB Vaccine Foundation.
So, why is TB, an ancient disease, continuing to plague us after 5000 years? There are many reasons and the speakers outlined these for us. The first is poverty. The disease spreads quickly through the air and so we are all at risk, but those living in poverty even more so. The second is the rise of the HIV/AIDS epidemic. 1/3 of the population is carrying a latent form of TB. Once your immune system is compromised it becomes much more likely you will progress to active TB. In fact, TB is the leading cause of death for HIV patients with up to 40% of HIV deaths being TB related. The third reason that TB is still with us is poor TB control programs worldwide and poor laboratory capabilities, especially in endemic countries.
A fourth reason is that the drugs we are using to treat TB all date from the 1940′s, 50′s and 60′s.We are treating this disease with very old technology.
This, together with (more…)
The World Health Organization (WHO) published their largest survey ever on multidrug-resistant tuberculosis (MDR-TB) on Tuesday. In summary, MDR-TB is more prevalent, and more in need of control, than ever.
“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 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.”
Read the full study here, some key findings below:
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- The WHO estimates that there are nearly 500,000 new cases of MDR-TB each year, about 5% of the approximately 9 million new cases of regular TB per year
- The highest rates of MDR-TB were found in countries in the former Soviet Union and China. China and India carry about half the global burden of MDR-TB and the former Soviet states another 7%. Rwanda had a noticeably high percentage of MDR-TB cases among TB patients (3.9%), but data on MDR-TB presence in Africa was rather limited in the study.
- Extensively drug-resistant TB (XDR-TB), a virtually untreatable form of TB, has been recorded in 45 countries.
- Surveys in Latvia and the Ukraine found nearly twice the level of MDR-TB among TB patients living with HIV compared to those without. In South Africa, 44% of TB patients are estimated to be co-infected with HIV.
- MDR-TB and XDR-TB are progressively more expensive and difficult to treat.
The 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. There is a total finance gap for 2008 of $ 2.5 billion, including a $ 500 million gap for MDR-TB and XDR-TB.
