Marking the World Tuberculosis (TB) day (March 24th), Host, Cell and Microbe featured a commentary¹ by Carl Nathan on TB-eradication challenges. Although perhaps this post would have been timely 2 weeks ago, it seemed very much relevant to NYTF’s theme, so here goes…

Today TB is the second-leading cause of infectious disease deaths after HIV/AIDS. According to WHO estimates, in 2005 alone, 1.6 million people succumbed to TB. As Carl Nathan describes, the incidence of TB has risen in the recent past, fueled by the pandemics of HIV/AIDS and type2 diabetes. Individuals coinfected with HIV/AIDS are more likely to develop active TB, and to make matters worse, the drugs prescribed for TB are incompatible with the antiretroviral therapy common for HIV/AIDS. As far as type2 diabetes, it is unknown why the condition leads to immunodeficient states towards Mycobacterium tuberculosis (Mtb). The struggle against TB has further been set-back by the emergence of drug-resistant strains of Mtb and the lack of any new drugs in the last 45 years to treat the infection.

The article summarizes hurdles we face to eliminate TB as a global health concern. Despite all advancements in basic and medical sciences, there still remain fundamental issues about Mtb we do not understand—for example, its life cycle and relationship to our host cells and the immune system, what drives it into and out of latency and what pathways it uses to evade elimination from the body. For the translational research community, challenges lie in the development of rapid diagnostic tools, newer vaccines and (faster-acting) drugs.

The article also touches upon broader issues that are relevant to global health concerns beyond TB. Given the current patent laws, there is little incentive for the pharmaceutical industry to commit vast amounts of resources to develop drugs for diseases endemic in the developing world, where people are too poor to pay for them. (A side note: drugs also have to be accessible at a reasonable cost—even if a percentage of population in poorer countries can afford them, high drug prices often create opportunities for some to illicitly distribute diluted drugs and make profits, while the lowered drug doses result in emergence of drug-resistant strains). As a solution, the author advocates the Health Impact Fund (proposed by Incentives for Global Health, the Fund would be financed by governments across the world. Patent holders could choose to apply to the Fund for rewards based on their product’s impact on the global burden of disease. I think the concept of the Health Impact Fund could merit a discussion by itself on this forum).

Carl Nathan also adds that discoveries that can make a significant difference to containing TB may not come from academia or industry alone, and suggests that public-private partnerships that combine the best of both sectors may turn out to be the most efficient collaborative models (Perhaps this is the best way to direct academic activities into translational research—a “bottom up” approach as Julie Lotharius suggested?) In the last decade or so, many agencies (mainly the NIH, The Bill and Melinda Gates Foundation and the European Union) have channeled resources amounting to over $400 million per year into TB-research, and public-private partnerships such as The Global Alliance for TB drug Development and Lilly TB Drug Discovery Initiative have been set up. While this is certainly encouraging, he points out that public institutions and the industry still need to work together to create business models that will allow sustainable research, development and distribution of medicines/vaccines to those in the world who need them but cannot afford them.

1. Nathan, C. (2009) Host, Cell and Microbe 5(3):220-224.