While the previous presenters at the Stop TB Symposium, held on October 30, 2013, just before the 44th Union World Conference on Lung Health in Paris, focused on the new Global Strategy — and the new target of TB elimination by 2035 (see recent posts) — Dr Christian Leinhardt of WHO’s Global TB Programme set the stage for the rest of the day, which was focused on the type of research that would be needed to reach that goal.
In order to achieve the new global strategy target of TB elimination by 2035, intensive research and innovation is needed to develop a combination of focused and high impact anti-TB tools, according to Dr Leinhardt. He believes one need only look back at when TB control was at its most effective for clues on how to direct those research efforts.
As noted in the Global TB Report 2013, the incidence of TB is being driven down globally, but at a very low rate, around 2 per cent each year. However, some regions are doing better; for instance, China and Cambodia are reducing the incidence of TB by about 4 per cent per year. There have also been times when TB incidence was brought under control more rapidly such as in Western Europe after World War II where the TB incidence declined by around 10% per year. But to achieve elimination by 2035, “what we want to achieve is a 20% reduction per year,” said Dr Leinhardt.
But is that even possible?
Dr Leinhardt said that there are historical examples where TB incidence fell quite sharply. In the 1950’s, 60’s and 70’s, there were dramatic declines in the incidence of TB among the Inuit and other indigenous peoples in Alaska, NW Canada and Greenland. In Alaska, the TB incidence fell by as much as 17% per year between 1955-1974.
What was the recipe for this success? Because of a combination of highly focused and high intensity interventions including: mass screening and treatment of latent TB infection, the decentralisation of TB care; the scale up of BCG vaccination; improved health access and social protection as well as, possible, economic development.
All that together brought a dramatic decline in global incidence.
Can we achieve something similar today?
Dr Leinhardt believes so, but “we need to shift the paradigm from thinking just about treatment to thinking about prevention”.
New tools (diagnostics, treatments and vaccines) are becoming available or are in the pipeline, but “we need to see how best to deal with these tools and how we can accelerate their impact,” he said.
Modelling studies suggest the use together of new tools acting on both transmission and reactivation pathways could have synergistic effects against the TB epidemic. Consequently, research to develop better diagnostics, treatments and preventive therapies should not be too narrowly focused but should be mindful of the new tool’s impact upon the larger health context.
Dr Leinhardt reviewed the International Roadmap for TB Research, which was launched at the 42nd Union World Conference on Lung Health in Lille, France. Its overall goal was to identify knowledge gaps and priority areas in TB research towards elimination of TB by 2050. It sought to develop the essential research questions for TB control that could lead to the elimination of TB, to strengthen each aspect of TB research and mobilise and focus resources into the most important areas.
“How can we accelerating research for TB elimination? We need point of care diagnostics to detect all TB; we need to treat all forms of TB in all patients, and we need to prevent TB in all populations in order to achieve TB elimination,” he said.
Dr Leinhardt believes the different TB research disciplines: basic research, vaccine development, drug development, diagnostic development, epidemiology/surveillance and operational research should integrate a cross disciplinary approach — looking not just at the product oriented endpoints, but at the effect of the intervention on TB transmission for instance — in order to contribute to a more public health outcome oriented science.
In addition to historical models, we need to conduct implementation science research to develop current models for TB elimination. Dr Leinhardt concluded with a description of a “Research for Elimination Initiative’ which will focus on countries in the ‘pre-elimination of TB phase’ and some selected countries in the ‘concentrated epidemic phase’. The initiative will study context specific strategies for elimination in these countries, in order to identify the optimal implementation of the various TB interventions. This should help identify global TB elimination champions and role models that can act as pathfinders, showing the way forward for global TB elimination.
 Grzybowski S, Styblo K, Dorken E. Tuberculosis in Eskimos. Tubercle 1976; (suppl.) 57: 1-58.