MDR-TB: overcoming resistance is essential
Dr Margaret Chan
Director-General of the World Health Organization
Honourable ministers, colleagues in the UN system, representatives of industry, ladies and gentlemen,
At a time of crisis, whether caused by economic downturn, a warming climate, or a new influenza virus, we need to look very carefully at areas of public health where any lapse in current efforts will bring us a much bigger bill very soon. Tuberculosis control is a prime example.
When I addressed the May World Health Assembly on the prospects of an influenza pandemic, I used the example of tuberculosis to illustrate an important point.
Influenza pandemics typically cause a large and rapid surge in the number of people seeking or needing medical care. This makes them socially disruptive, but it also creates significant challenges for health services. Even before WHO announced the pandemic, health services in some very wealthy countries were having difficulty coping.
In the developing world, where health systems are already stretched to the breaking point, we have to anticipate great challenges in coping with the added pressures introduced by an influenza pandemic.
The 2009 influenza pandemic, which we announced last week, is the first to occur following the emergence of HIV/AIDS and the related resurgence of tuberculosis and its drug-resistant forms. Today, the survival of millions of AIDS and TB patients depends on uninterrupted supplies of medicines and uninterrupted access to basic health services.
What will happen if the world finds itself at the end of an influenza pandemic, only to discover that it is now under threat from a vastly intensified epidemic of multi-drug resistant or extensively-drug resistant TB? We have to be concerned.
We know, too, that the vast majority of cases of severe and fatal H1N1 infections have occurred in people with underlying medical conditions, including respiratory disease.
What will happen if the pandemic fuels higher morbidity or mortality rates for TB, just as the HIV/AIDS epidemic fuelled the dramatic comeback of TB? As I said, we have to be concerned.
Ladies and gentlemen,
Last year, the WHO report on anti-TB drug resistance documented the highest levels of multi-drug resistant TB , or MDR-TB, ever recorded in a general population. The 2009 WHO TB Report estimated that more than half a million new cases of MDR-TB occurred during 2007.
Even more alarming, well over half of these cases were resistant to multiple drugs right from the start, and not as a direct result of substandard treatment. This is the true alarm bell. This tells us that resistant strains are now circulating in the general population, spreading widely and largely silently in a growing pool of latent infection.
This is the true warning signal. If MDR-TB is not vigorously addressed, it stands to replace the mainly drug-susceptible strains currently responsible for 95% of the world’s TB cases.
Even more ominous is the emergence of extensively drug-resistant TB, or XDR-TB, which has now been reported in 55 countries. In most low-income countries, especially in Africa, the magnitude of the problem is unknown, as this form of TB is so difficult to diagnose.
But we do know this: unchecked, XDR-TB could take us back to the treatment era that predates the development of antibiotics.
Preventing and managing drug-resistant TB is a global health imperative. The agenda for doing this fits well with the agenda for strengthening health systems.
Sound basic TB control is the best way to prevent drug-resistant TB. Fundamental weaknesses in health systems impede sound TB control. We need bold new policies to counter major problems, such as the uncontrolled prescription of anti-TB drugs of uncontrolled quality and unknown efficacy.
Substandard treatment of normal TB drives the development of multi-drug resistant strains. In turn, substandard treatment of MDR-TB drives the development of XDR-TB.
Equally of concern, drug-resistant TB creates enormous additional demands and pressures on components of the health system that are already weak.
Compared with normal TB, the costs of treating MDR-TB can be as much as 200 times higher, and this is when the country benefits from the concessional prices offered by the Green Light Committee initiative. If drugs are procured on the open market, the price increase can soar 1000-fold. Either way, patients and their families face catastrophic expenditures.
The complex demands of treating drug-resistant TB touch the entire health system. Intensive treatment adds pressure to an already acute shortage of health workers. The costs add pressure to already underfunded services. The need for high-quality laboratory services is absolute, as is the need for strict procedures of airborne infection control in hospitals and other health facilities.
For multi-drug resistant TB, the currently recommended second-line treatment regimens are complex, of long duration, and require intensive monitoring of adverse events and treatment outcomes. Stringent efforts and social support are needed to ensure treatment adherence.
In other words, drug-resistant TB severely strains and erodes the very capacities needed to prevent it in the first place.
We can look at this another way. The emergence of drug-resistant forms of TB represents a failure, not just of the TB control programme, but of the entire health system in which the programme operates.
Ladies and gentlemen,
Crises and setbacks can stimulate the best in human courage, creativity, and innovation. This panel will be looking at ways to fund and implement innovation.
In April of this year, WHO co-hosted a ministerial meeting, held in Beijing, on drug-resistant forms of TB. This high-level meeting resulted in a call for action. That document included a clear call for substantially increased investment in research and development for new diagnostics, medicines and vaccines.
The response to TB has already brought us a number of pioneering innovations that have opened up new ways of tackling several other diseases, especially concerning the procurement and management of medicines.
Fixed-dose combinations were developed specifically to reduce the risk of drug resistance. Logistically, they are easier to store and distribute. Prices are the same as, or lower than, loose pills, and treatment is easier to finance. Yet these drug formulations are still underutilized in nearly all high-burden countries.
Global control of MDR-TB will depend, ultimately, on wide availability of newly developed rapid diagnostic tests. These tests are capable of diagnosing TB within hours, and without complex equipment or laboratory bio-safety requirements.
Global control will also depend on the development of new drugs to shorten MDR-TB treatment from years to a few months and a vaccine for prevention.
Since 1993, when WHO declared tuberculosis a global health emergency, control has advanced by identifying obstacles and then devising or revising a strategy to overcome them. We need to do so again now, as an international community, for the sake of global health security, and with a most appropriate sense of urgency.
Innovative R&D can deliver the huge jump ahead we so badly need.
Thank you.