Stopping the World's Biggest Infectious Killer
Diseases that have plagued humanity since ancient times continue to hold billions of people back, and tuberculosis is one of the most significant among them. Today, there are an estimated 10-million-plus new TB cases each year, and the disease causes more than 1.6 million deaths, earning it the dubious honor of being the world’s number one infectious killer.
While training as a doctor in India, where TB is more prevalent than in any other country, I saw first-hand its devastating impact on individuals, families and entire communities.
Since my time as a medical trainee, I have been encouraged to see modest progress. Globally, the mortality rate dropped 42 percent from 2000 to 2017. New diagnostics and medicines are now available, including bedaquiline, which is proving to be a potential game-changer for drug-resistant TB—and countries like South Africa have successfully rolled it out. Political commitment is also on the rise, with heads of state agreeing to mobilize $13 billion for TB care and prevention by 2022 at a high-level meeting in September, 2018.
Yet one of the most frustrating challenges in the TB epidemic perseveres: the lack of adequate 21st-century tools to fight what’s now a 21st-century epidemic. Despite recent scientific advancements for many diseases, patients and care providers continue to rely on antiquated, inefficient diagnostics, vaccines and drug regimens.
This is unacceptable.
Take vaccination. The BCG vaccine we use for TB today was developed in the 1920s, and has limited efficacy. What about diagnostics? The most widely used test for TB dates back to German scientist Robert Koch, who identified the tuberculosis bacterium under a microscope in 1882, and it is barely 50 percent sensitive. How can we defeat TB if we have no good vaccine and can only detect it half of the time?
For those who do get an accurate diagnosis, the complexity of treatment is another major problem. Existing medications require drug-resistant TB patients to take medicine every day for two years—a regimen to which it is extremely difficult to adhere. If we are going to end the epidemic, we must raise the level of ambition and reimagine how TB care is delivered.
Finally, even when patients are accurately diagnosed and adhere to treatment, success is not a foregone conclusion. Multidrug-resistant tuberculosis (MDR TB) is complicating the global response. In 2017, an estimated 3.6 percent of all new cases were drug-resistant, of which India, China and Russia accounted for almost half. While bedaquiline is a step forward, it still not widely available and accessible. We need to continue improving our options. Allowing resistance to spread further could lead to a surge in the epidemic.
New research investments will be critical to fill these gaps. Just this week, Policy Cures Research released its annual G-FINDER report, the world’s most comprehensive analysis of neglected disease research investments. According to the report, funding for TB R&D globally increased by $23 million to $615 million between 2016 and 2017—a cause for cautious optimism. And it is particularly exciting that domestic funding in India more than tripled during the same period.
However, the report also shows that we are still falling well short of the funds needed for science and innovation in TB and other diseases. Moreover, the concentration of existing funding among the same major donors is cause for concern; in 2017, the top 12 funders accounted for 90 percent of all R&D funding and the top three funders (the U.S. National Institutes of Health; the Gates Foundation; and private industry) collectively contributed just over two thirds. We need both more investment, and more diversified investment, if we are to end the TB epidemic. We also need countries with high TB burden, especially Brazil, Russia, India, China and South Africa (known collectively in the public health world as BRICS), to step up and lead the research agenda.
Financial gaps directly translate into gaps in care. As a doctor and a scientist, I find it impossible not to be an advocate as well. Fortunately, there has never been more momentum than there is today, with virtually unanimous agreement on the massive potential of R&D to change the game for infectious disease. This is largely because we have seen it work: from the Ebola vaccine to antiretroviral therapy for HIV to bed nets to prevent transmission of malaria. Moreover, governments around the world have committed to providing significantly more funding by 2022 for TB R&D, signaling growing political will. Now is the time to science the shit out of TB and hold government leaders accountable to their commitments.