World must respond to threat of drug-resistant tuberculosis

Ann Silversides

doi:10.1503/cmaj.090695

The spread of multidrug-resistant tuberculosis (TB), deemed a “time bomb” by the head of the World Health Organization (WHO), has led more than 30 nations to commit to a series of prevention and control measures.

WHO Director General Dr. Margaret Chan told an Apr. 1–3 conference in Beijing, China, that the situation is “potentially explosive.”

The “unregulated availability” of TB medicines is promoting the development of both multidrug-resistant and extensively drug-resistant TB. (The former is resistant to the 2 most powerful first-line TB drugs; the latter is also resistant to the most powerful second-line TB drugs.)

FIGURE. Demonstrators protest in Cape Town, South Africa, demanding new strategies to curb the spread of tuberculosis. World Health Organizations officials say that a tuberculosis crisis will ensue if drug-resistant strains of the disease are not contained. Image courtesy of Reuters/Mike Hutchings

As well, more than 90% of the estimated 500 000 new cases a year of drug-resistant TB are not being diagnosed and treated according to international guidelines, the WHO says.

Global momentum is necessary to meet the challenges, South Africa’s Minister of Health Barbara Hogan told a press conference. “Countries need to share best practices, research and laboratories.”

South Africa, China, India and the Federation of Russia account for 60% of the global number of multidrug-resistant TB cases, with South Africa bearing a high burden of HIV/AIDS and TB coinfections. (Worldwide, almost one-quarter of the total 2 million HIV deaths in 2007 were among people coinfected with TB — double the number reported in earlier years, according to the WHO 2009 TB report.)

Conference participants pledged to tackle problems including substandard care and low quality drugs, health work-force shortfalls, the pressing need for new or revitalized laboratories and lab technicians, and limited access to fixed-dose combinations of first-line drugs.

As well, they agreed to develop national plans, remove financial barriers to care and develop tools to combat extensively drug-resistant TB. In 2008, 55 countries reported at least 1 case of this type of TB.

New projections about the emergence of extensively multidrug-resistant TB prompted the WHO to recalculate the price tag for meeting the target set in the Global Plan to Stop TB. Almost $17 billion will be needed to treat 1.4 million cases by 2015, with the costs for 2015 ($4.4 billion) being 61 times the funds committed for 2009 to the Global Plan to Stop TB.

Countries will be expected to invest up to 80% of the costs, with the remaining 20% coming from international sources.

Diagnostic tests and treatments for TB are antiquated, said Dr. Peter Small, senior program officer for TB at the Bill and Melinda Gates Foundation, while announcing a $33-million joint project with China. Six new diagnostic tools and treatments for multidrug-resistant TB will be tested. The best will be “scaled up” to millions of people within 5 years.

Shortly before the conference, the Canadian International Development Agency announced a $127.4-million contribution to fight global TB, of which $7.4 million is for the WHO Global TB Program.