Tuberculosis (TB) has been with us for thousands of years—an airborne respiratory illness that by 1882 was the cause of an astounding one of every seven deaths. In spring of that year—March 24, to be exact—Dr. Robert Koch announced he had isolated the bacteria that cause TB. His discovery led to a test to detect the disease, a vaccine to prevent it, and, eventually, antibiotics to treat it. But TB is a complex disease, and despite advances, it continues to kill nearly a million and a half people each year.
Every March 24th, those who are working to stop TB—including our team at PATH—take the opportunity to commemorate Dr. Koch’s work and bring attention to tuberculosis. This year, the theme of World TB Day is “stop TB in my lifetime.” Considering the disease’s long history, is that possible? We asked Dr. S.S. Lal, who recently joined PATH as TB technical director for our HIV/AIDS and Tuberculosis Global Program.
Dr. Lal: The question is simple, the answer is not. Yes, theoretically it is possible to stop TB. The TB community has set a target to eliminate TB by 2050. Elimination means there will be less than one new TB case per million people per year. Right now, there are more than a thousand cases per million people per year, so you can see elimination is a very ambitious target.
We have to diagnose TB, treat it, and cure it. We also have to prevent it. And there are challenges in each of these.
A cough or something serious?
Let’s start with diagnosis. A primary symptom of lung TB is coughing. People may not automatically think of TB when they are coughing. And when health care providers fail to suspect TB in a patient, diagnosis can take even longer.
Easier diagnostic tests are available, but they’re not very sensitive, and the gold-standard tests can take a few weeks to confirm TB. So by the time people are diagnosed, they may already be very sick.
Drugs and drug resistance
We do have medicines that can cure TB, but there are problems here too. The minimum period of treatment is six months, so some patients will interrupt or stop their treatment. Irregular, inadequate, or incomplete treatment can cause death, and it can contribute to the development of drug resistance—TB that will not respond to first-line anti-TB drugs.
It’s true that we do have a TB vaccine, but it protects only children from severe forms of TB since immunity wanes as children grow up.
More support, better outcomes
So, what I’m saying is it’s going to be a tough task to stop TB, but it’s not impossible. The global TB community is proposing bolder targets for TB control—75 percent reduction in mortality between 2015 and 2025. In order to reach that goal, we need universal access to care for all forms of TB, in adults and children.
We need quicker, easier, and cheaper diagnosis that can be done at the point of care—wherever people are accessing health care. We need new and efficient drugs that can reduce the duration of treatment for both drug-susceptible and drug-resistant TB. We need to come up with a long-lasting vaccine that will protect people for their entire lives. Most importantly, we need additional resources to support these efforts. It’s estimated that the current annual funding gap for TB control is about $3 billion.
These are big challenges, but remember: we can already diagnose this disease, and we can already treat it. I’m optimistic that we will have improved diagnostic tools, better medicines, and more efficacious vaccines in the near future. I’m sure we can get better at managing TB. And that gives me the hope that we’ll stop TB.