We neglect ancient killers like tuberculosis at our peril
It was March 24, 1882, and a little-known German physician named Robert Koch was about to make history. A group of scientists were gathered at a meeting of the Berlin Physiological Society, a body that had for years tried to uncover what was behind the world’s deadliest scourge: tuberculosis — or “consumption,” as it was called in the 19th century. The disease was spreading across Europe and the United States, killing one in seven people. Many scientists had attempted to discern the root cause of the disease: Some thought it was the result of foul air, or “miasma”; others were sure it was hereditary. The germ theory of disease was only in its infancy, but that was about to change.
Koch revealed to his assembled colleagues that he had found the cause of tuberculosis: a germ he called Mycobacterium tuberculosis. Another notable German scientist,
Paul Ehrlich, who would discover the first effective treatment for syphilis, was in attendance and described Koch’s address as the “most gripping experience” of his scientific life. Koch’s discovery was of such significance that he would go on to win a Nobel Prize in 1905. To this day, the World Health Organization (WHO) marks World TB Day every year on the anniversary of Koch’s landmark announcement.
Tuberculosis is no longer a disease that kills because of a lack of scientific understanding. It has transformed into something arguably worse: It has become a disease of neglect.
At present, about a quarter of the global population is estimated to have been infected with the tuberculosis bacterium (a significant but hotly debated number). The bacteria lie dormant in most people who live with tuberculosis in this latent and symptomless form; they are not contagious. But over time, the immune system can weaken — from age, illness, or medications. In 5 to 10 percent of those people, the bacteria will shirk the body’s defenses that keep disease at bay, and they will develop active tuberculosis, which typically includes symptoms like severe fatigue, drenching night sweats, and hacking bloody coughs that catapult bacteria-laden respiratory droplets into the surrounding air. This is how TB spreads. In 2022, the latest year for which we have complete data, the WHO reported that 10.6 million people were sick with active tuberculosis. An estimated 3,200 people die daily as a result of this curable disease.
If scientists have understood what causes tuberculosis for 142 years, how can this be? The answer is complacency.
Before the advent of antibiotics, the only treatment was ample rest, fresh air, and sunshine. For the rich, this meant prolonged stays in comfortable, country club-like sanatoriums.
The 1950s and 1960s brought medical advances, namely effective antibiotics such as rifampin, isoniazid, pyrazinamide, and ethambutol. Today, most tuberculosis cases require four to six months of daily antibiotics, a long and arduous course that can produce toxic side effects such as vomiting and nausea, rash, and risk of liver inflammation.
Completing TB treatment as prescribed usually means the patient will fully recover. But not all patients take all of their antibiotics. That means the infection lingers and can morph into something even more deadly: drug-resistant
TB. To stop this from happening, making treatment easier (and shorter) is key.
We’ve been using the same frontline antibiotics to fight TB since the mid-20th century. In fact, the development of drugs to fight tuberculosis essentially ceased for more than 40 years, and there’s only one available vaccine against TB, which was developed in 1921 and provides just partial protection for children. Why?
Antibiotics in general are not big business. Ninety percent of tuberculosis patients live in developing countries, and the profit margin for the pharmaceutical companies developing the antibiotics is small. Drug companies aren’t always motivated to undertake sometimes decades-long efforts to develop new drugs — even if the current crop is far from ideal.
In 2012, the US Food and Drug Administration approved the first new TB drug in 50 years, bedaquiline: a medication developed by Johnson & Johnson to treat drugresistant TB. This is a welcome development, but drugresistant TB exists in large part because people with drugsusceptible TB didn’t finish their treatment, allowing the bacteria to mutate into this much more dangerous form. Drug-resistant TB is here to stay, but we can prevent more TB cases from becoming impervious to available antibiotics if we make frontline treatments shorter and better.
Add stigma to this, which causes people to delay seeking treatment or to forgo it altogether. The falsehood that TB is hereditary, or that you get it from being poor, persists in spite of the fact that Koch settled the matter a century and a half ago. In the tuberculosis clinics where I have worked, I have often heard different versions of these misinformed notions.
Nevertheless, many of my TB patients do live hardscrabble lives, making it harder for them to get diagnosed and access treatment. They might live in overcrowded shelters or have been incarcerated at some point. Nearly all of them are society’s marginalized, and that is where the disease finds them — at the margins.
I try to envision a better future for such patients: governments and private stakeholders working together to fund surveillance programs, which would help detect and track TB cases; getting rid of antiquated diagnostic techniques like sputum smear microscopy, which can be unreliable; and reducing stigma. Science has managed this with other diseases that invite prejudice and misunderstanding, like HIV/AIDS. Furthering research efforts could spur drug and vaccine breakthroughs that would prevent tuberculosis infections in the first place and allow for treatment protocols that are shorter and less toxic for those who must take them.
People ask me if tuberculosis is a forgotten plague. “Yes,” I tell them. And it desperately needs our attention.