March 24, 2017
Statement of Christine F. Sizemore, PhD., Richard Hafner, M.D., and Anthony S. Fauci, M.D.
National Institute of Allergy and Infectious Diseases
National Institutes of Health
Tuberculosis (TB) is one of the world’s most devastating infectious diseases. March 24th marks the day in 1882 when German microbiologist Robert Koch announced he had discovered Mycobacterium tuberculosis, the bacterium that causes this ancient scourge. Today, in recognition of World TB Day, the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), reasserts its commitment to improving our understanding of TB and how to prevent, diagnose and treat it. Around the globe, researchers and the public health community are united in working toward these goals.
TB is the world’s leading cause of death from an infectious disease, especially among women and children. The World Health Organization estimates that more than 1.8 million people worldwide died of TB in 2015. The symptoms of the disease, which is transmitted through the air and primarily affects the lungs, often begin with coughing, shortness of breath or swollen lymph nodes—but can end in death if left untreated. People with HIV are especially vulnerable: of deaths among people co-infected with HIV and TB, about one quarter are due to TB. In addition, the World Health Organization estimates that about one-third of the world’s population is infected with “latent” TB, in which people carry the bacterium while exhibiting no symptoms. Five to 10 percent of these latent TB carriers risk developing active TB at some point in their lifetimes. For latent TB carriers who are infected with HIV, this risk is approximately 10 percent per year. Finally, it is important to note that smoking substantially increases TB disease occurrence and risk of death due to TB worldwide.
A safe and highly effective vaccine against TB will be a critical tool in ultimately controlling the infection. Currently, the only available vaccine against TB is bacille Calmette-Guerin (BCG), developed in 1921. While this vaccine offers protection against disseminated disease and death in children, it is much less effective against the transmissible pulmonary form of the disease in adults. NIAID supports research across the spectrum of basic, preclinical and clinical development to arrive at innovative new approaches toward the development of vaccines to prevent this disease.
The rise in incidence of multidrug resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis is of critical concern. Patients with MDR-TB may require more than 2 years of treatment, which can be extremely costly and particularly difficult in resource-limited settings—especially because the side effects of treatment can be severe. XDR-TB is even more difficult to treat, and for some patients, no effective drugs are available. NIAID contributes to the National Action Plan for Combating MDR-TB through its support of research into new diagnostics, as well as antibiotics and other therapies to combat the growing problem of MDR-TB and XDR-TB. For instance, trials being run through some of the programs in NIAID’s HIV/AIDS Clinical Trials Networks will test the efficacy of the drug bedaquiline against MDR-TB. In a separate trial, a combination therapy using both bedaquiline and delamanid will also be tested against MDR-TB.
In collaboration with research institutions and international organizations, NIAID continues to support advances in TB product development. In June 2016, a NIAID-hosted conference titled “New Approaches to Combating Tuberculosis: Leveraging NIH Intramural TB Research for the Global Effort,” brought together researchers from various institutions throughout the world to discuss ongoing efforts and collaborations. NIAID also co-hosted two workshops on new drugs with the Stop TB Partnership in 2016.
As part of NIAID’s focus on improving TB treatment, we also are investigating supportive approaches to help patients during the treatment of their disease. For example, some TB drug regimens require such strict adherence that patients must be observed by a health care professional as they take their daily medication. This is a costly and time-consuming precaution necessary to ensure full recovery and prevent complications. Recently, NIAID-supported trials began to investigate whether mobile technology could replace the need for more frequent in-home visits by health care professionals. Other programs administered through the HIV/AIDS Clinical Trials Networks are researching how to prevent an infection with MDR-TB after close exposure to a case, and whether a 1-month regimen could be effective at preventing TB infection.
Detecting infection early is key to minimizing suffering caused by TB, and NIAID is working to develop and refine diagnostic tools for TB. In this regard, we contribute to global consortia that are mapping the genetic diversity of MDR or XDR strains of Mycobacterium tuberculosis. NIAID’s Tuberculosis Research Units Network program has helped identify biomarkers that define the various stages of infection. International collaboration is key to establishing clinical research capabilities and patient cohorts, which will facilitate future research into the clinical and pathologic characteristics and spread of different TB strains in India, Brazil, Indonesia, South Africa, and other parts of the world.
The World Health Organization estimates that 43 million lives were saved between 2000 and 2014 as a result of improved diagnosis and treatment of TB. Sustained biomedical research is key to continuing to advance medical countermeasures against TB. Through ongoing and future research initiatives, and collaboration with other funding agencies and organizations, NIAID is dedicated to saving and improving the lives of people with TB.
Anthony S. Fauci, M.D., is Director of the National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health in Bethesda, Maryland. Richard Hafner, M.D., is chief of the TB Clinical Research Branch in the NIAID Division of AIDS; Christine F. Sizemore, Ph.D., is chief of the Tuberculosis and other Mycobacterial Diseases Section in the NIAID Division of Microbiology and Infectious Diseases.