By Christian Lienhardt, Senior Scientific Adviser, Stop TB Partnership
With 8.8 million new cases and 1.4 million deaths worldwide in 2010, TB remains an unacceptable burden of human suffering and loss, overwhelmingly borne by poor and vulnerable people living in low or middle income countries. The tools available for TB control are old, lack effectiveness, and are not readily accessible in many settings. In most highly affected countries the diagnosis of pulmonary TB still relies on sputum microscopy, a century old technology that only detects half of cases. Current treatment of tuberculosis, which was developed in the 1970s, demands close supervision, is difficult to use in people living with HIV, and cannot be used in patients infected with multi-drug resistant strains. The only TB vaccine (BCG), first used in 1922, is variable in its efficacy to protect adults from pulmonary TB. More effective and widely accessible tools are needed to make a greater impact on the global TB burden in order to reach the goal of eliminating TB by 2050, defined as less than one case per million population in the Global Plan to Stop TB 2011-2015.
Fortunately there is hope, thanks to notable progress in the development of new tools for TB control over the last decade. In diagnostics the recent introduction of Xpert MTB/RIF - a DNA-based molecular assay that can diagnose TB and the presence of rifampicin-resistance in 100 minutes - is a major breakthrough. For treatment, nine new drugs are currently in phases I to III clinical trials. For vaccines, four novel candidates are presently in phase II clinical trials and two have recently entered phase IIb trials.
These advance alone are, however, insufficient. A recent mathematical model suggests that to effectively control and eliminate TB by 2050 a combined and synergistic implementation of several novel strategies is needed. These strategies include improved diagnosis of drug-susceptible and drug-resistant TB, shorter treatment of overt TB cases, scaled-up treatment of latently infected persons, and mass vaccination campaigns using a more effective vaccine. This could be obtained only through massive synergistic efforts in all areas of research and development.
"What research is required to Stop TB?"
Research across the full continuum - from basic science for discovery, to development of new diagnostics, drugs and vaccines, and their optimal uptake for better TB control - is necessary to enable the revolution in TB control technology needed to achieve the goal of TB elimination by 2050. For this, we need to improve our understanding of the basic science that will fuel the development of new diagnostics, drugs and vaccines, and we need to ensure that the newly developed tools are acceptable and affordable to be effectively used where they are needed. To achieve these objectives all aspects of research must be properly addressed and funded in a harmonized way.
To support this, the TB Research Movement engaged in the development of a coherent and comprehensive roadmap for global TB research towards TB elimination that encompasses all aspects of research. This roadmap was developed through a coordinated process including a multidisciplinary Delphi consultation, a series of systematic reviews and an open web-based survey. It involved a multidisciplinary group of more than 150 scientists, TB experts, implementers, funders and community advocates from around the world. Critical research priorities were identified in the areas of epidemiology, fundamental research, research and development of new diagnostics, drugs and vaccines, and operational and public health research. More than a simple research agenda, the International Roadmap for Tuberculosis Research outlines critical and priority areas for future scientific investment, with the aim of increasing and harmonizing funding across the research spectrum.
This roadmap provides an architecture on which transformational and outcome-oriented research areas can be constructed. It is intended to promote organization of cross-disciplinary teams and attract all research-related constituents to the field, especially those in BRICS countries, who have a vital role to play. It provides a common platform for donors, researchers, implementers, and advocates by identifying the most important research questions.
The roadmap appears at a critical moment, when funding for TB research has flattened for the first time since 2005. A report released recently by the Treatment Action Group and the Stop TB Partnership found that in 2010 just US$ 617.1 million was spent on TB research and development globally, down 0.3% compared to 2009 funding levels - while the Global Plan to Stop TB 2011-2015 calls for at least US$ 9.8 billion in TB research funds over the plan’s five-year period. It is hoped that the research roadmap will serve as a framework for concrete actions to synergize TB research efforts globally and catalyse the development of new research collaborations to address difficult and as yet unanswered questions in TB.
This opinion piece was published on 27 January 2012 in Speaking of Medicine - PLOS Medicine community blog.