By Mario Raviglione and Matteo Zignol, Stop TB Department
In the occasion of World TB Day 2010, the World Health Organization (WHO) issued a new report "Multidrug and extensively drug-resistant (M/XDR-TB): 2010 global report on surveillance and response," which documents the highest levels of MDR-TB ever recorded. Both MDR and XDR-TB are taking a huge global toll in terms of risk of infectious cases spreading out of control, draining of current limited resources, and investments in health, and lives needlessly lost.
WHO estimates that, worldwide, 440 000 people had MDR-TB in 2008 and that a third of them died. In sheer numbers, Asia bears the brunt of the epidemic as almost 50% of MDR-TB cases worldwide are estimated to occur in China and India. In 2008 up to 28% of new patients with TB were diagnosed with multidrug-resistant forms in oblasts of northwest Russia, including regions sharing borders with the European Union. In Africa, where little data is available, an estimated 69 000 cases emerged in 2008, but the vast majority of them went undiagnosed. No precise estimates are yet available on the global number of cases of XDR-TB, but limited evidence suggests there may be around 25 000 a year with most cases being un-recognized and fatal. Since XDR-TB was first defined in 2006, a total of 58 countries have reported to WHO at least one case of XDR-TB.
Drugs used to treat M/XDR-TB are less potent, more toxic, and much more expensive than the drugs used to treat standard TB: while a course of standard TB drugs costs approximately US$20, MDR-TB drugs can cost US$5000 or more, and XDR-TB treatment is far more expensive. The Global Plan to Stop TB, a plan promoted by all Stop TB Partners world-wide, estimates that, in the 27 countries with the highest burden of MDR-TB (85% of the global burden), 1.3 million M/XDR-TB cases will need to be treated between 2010 and 2015 at a cost of US$16 billion over six years, rising from US$1.3 billion in 2010 to US$4.4 billion in 2015. Funding needed for MDR-TB control in 2015 will be 16 times higher than what is currently available in real terms in 2010.
Tuberculosis programs and national health systems in general face tremendous challenges when addressing M/XDR-TB. But there are encouraging signs that, even in the presence of severe epidemics, governments and partners can turn around MDR-TB by (i) strengthening basic TB control to stop the production of drug resistance and (ii) implementing WHO recommendations for rapid identification and proper treatment of existing M/XDR-TB cases. For example, following significant efforts made during the past five years in Tomsk and Orel Oblasts in the Russian Federation, where already high levels of MDR-TB were still rising until recently, we are now seeing a reversal which confirms that severe MDR-TB epidemics can be halted and turned around where sufficient will and resources exist. These two Russian regions now join other countries and areas that have made major progress in recent years such as Estonia and Latvia, besides low-burden settings such as the U.S. and Hong Kong. In Western Europe, MDR-TB trends remain stable with no significant changes over the years.
Progress remains slow in most other countries. A critical concern is lack of information. We still do not know how many MDR and XDR patients there are in some high-TB burden countries. Worldwide, only 7% of all estimated MDR-TB patients are being diagnosed and notified. This points to the urgent need for improvements in laboratory facilities, access to rapid diagnosis, treatment with more effective drugs and regimens shorter than the current two years, and better models of care to support patients while in treatment.
WHO is at the forefront of the international response against M/XDR-TB, working closely with governments and partners to help them conduct surveillance of drug resistance, strengthen service infrastructure for proper care, and put in place effective approaches. Lately, WHO has embarked with the Foundation for Innovative New Diagnostics (FIND), UNITAID, and the Stop TB Partnership's Global Drug Facility in a five year project to strengthen TB laboratories to allow use of new rapid molecular tests in 27 highly affected countries so that life-saving treatment can be started earlier. WHO has also been working closely for a number of years with the Global Fund against AIDS, Tuberculosis and Malaria, UNITAID, USAID, CDC, PEPFAR, and others in the international community to increase access to vital second-line drugs. But we can only succeed through the full support of, collaboration between, and continued leadership of a wide range of actors, from country governments to multi-lateral organizations, from the international donor community to private sector players and civil society.