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Two images are taped side by side on a grey background. The image on the left is a black-and-white historical image of a female patent, looking at a camera while a male doctor in a labcoat listens to her lungs via her back with a stereoscope. Below the image is text that says “Seattle, 1927.” The image on the right is in color and shows a male doctor wearing a mask and lab coat holds a stethoscope to the bare back of a female patient, listening to her lungs. The text “Bavaria, 2022” is below the image.

Tuberculosis, not COVID-19, is the plague of the century

Wealthy nations are preparing for a future pandemic while ignoring an ancient scourge: TB, a lethal disease that infects 2 billion people worldwide.
Filed Under
Written by
Vidya Krishnan
Photo illustration by
Mary Delaware
March 21, 2023
Read Time
7 min


Albert Camus wrote in his 1947 novel, The Plague, “What’s true of all the evils in the world is true of plague as well. It helps men to rise above themselves.” But the reverse is also true. The COVID-19 pandemic will be remembered as much for its unprecedented innovation in vaccine and drug development as it will be for the greed, hate, and fear it spurred.

For people who don’t live in rich nations with ample access to vaccines and effective treatments, the flaws in the global health system’s pandemic response existed long before Sars CoV-2 made landfall. In fact, for much of the world that virus is not even our deadliest enemy. The plague of our time is in fact an ancient killer: tuberculosis.

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Tuberculosis was the world’s deadliest infectious disease before COVID-19 swept the world. “We forget that TB killed over a billion people in the 19th and 20th centuries,” said Mike Frick, co-director of the Treatment Action Group’s tuberculosis program. “That’s a staggering death toll…most families on this planet have had someone affected by TB.” Today, about a quarter of the world’s population (2 billion) lives with a latent TB infection, meaning the bacteria has infected them, but they have no symptoms of the disease. There is roughly a 5 to 15 percent chance that a case of latent TB will develop into the active disease over a lifetime.

COVID-19, of course, has also affected nearly every family on the planet, with at least 758 million confirmed cases of COVID-19 worldwide, and 6.8 million documented deaths. Some estimates count more than 20 million deaths. But in 2021, in the teeth of COVID-19, millions of people fell sick with TB, many of them uncounted because many TB treatment and services halted during pandemic lockdowns.

Today, about a quarter of the world’s population (2 billion) lives with a latent TB infection, meaning the bacteria has infected them, but they have no symptoms of the disease.

It’s now clear that the two pathogens—novel virus and ancient bacterium—work as an efficient tag team, each amplifying the other. Plagues, after all, are shaped by other plagues. We are witnessing a moment of extraordinary vulnerability in global health as new plagues, far from supplanting old ones, are making them worse.

Pandemic lockdowns meant millions of TB patients went undiagnosed and untreated, increasing the risk of even more community spread in years to come. Within global health, this problem has come to be known as “the missing millions.” Globally, the estimated number of TB deaths increased between 2019 and 2021, reversing years of success in reducing mortality between 2005 and 2019.

Dr. Lucica Ditiu, head of the World Health Organization’s Stop TB Partnership, said in 2022, “We now have a very dangerous situation on our hands. Infections have been…allowed to fester and develop into advanced forms of the disease, and ultimately leading to higher death rates…every single human being should be up in arms and demand that their governments take immediate action. Everyone is now at risk.”

The long failure to treat TB as an urgent threat is, by itself, a tragedy. Unlike unprecedented investment in COVID-19 vaccines and therapies (because, as critics often say, COVID-19 affected wealthy nations, too), funding for TB has remained “pathetically low,” as Ditiu bluntly put it.

TB faded from the rich world nearly a century ago and is a case study in what happens when pestilence no longer scares the wealthy. There have been no new vaccines against TB in a century. No treatment advances since the 1950s. And of course, new, untreatable strains of the disease have emerged unchecked (multiple drug-resistant TB). TB has become a twenty-first century disease being fought with nineteenth-century tools as newer drugs remain locked in legal red-tape.

With TB snowballing, rich nations have already moved onto preparing for future pandemics, including investments in developing antivirals and vaccines for a “Pathogen X,” a placeholder name adopted by the WHO. While it’s important to invest in pandemic preparedness, it is often baffling to low-income nations that the WHO and high income nations fail to recognize that we’re already dealing with a fast-mutating Pathogen X: tuberculosis, a constantly evolving, drug-resistant, formidable enemy that continues to claim its victims with ruthless, mathematical efficiency.

TB faded from the rich world nearly a century ago and is a case study in what happens when pestilence no longer scares the wealthy.

We don’t need to wait for another threat to arise. TB is here. It’s been here for centuries.  “It’s like we are looking to put our money in something unidentified instead of focusing on what’s right in front of us that would serve to prepare for the pandemics to come,” Frick said.

The chronic underinvestment in TB drugs, diagnostics, and vaccines also means many of the worst affected parts of the world lack access to them. Health and humanitarian groups like the Treatment Action Group, Medicins Sans Frontieres (MSF), and Partners in Health have launched a campaign to demand that countries make the shortest therapies available to patients: a one-month course of antibiotics to treat latent TB; four months for drug-sensitive TB disease, and six months for drug-resistant TB—by the end of 2024. These therapies exist, but are not widely available. The current available regimen requires six months of daily antibiotics to treat most forms of TB, and sometimes years to treat drug-resistant TB. But for the first time in a century, there has been landmark progress in drug development. The novel, six-month regimen for drug-resistant TB, in particular is a huge breakthrough. We must stop treating patients with long regimens of toxic medicines, sometimes for years, when more humane care is available.

With the COVID-19 emergency slowly ebbing, the most immediate global health priority is to adequately fund the TB response. For the first time ever, funding for TB research and development reached $1 billion, but Treatment Action Group executive director Mark Harrington says we need at least $5 billion per year to meet the 2030 Sustainable Development Goal to eradicate TB. Tereza Kasaeva, director of the WHO’s Global TB Programme wrote in an email response, “TB will continue to be one of the most urgent global health threats unless immediate action is taken in the form of funding for drug and vaccine development, and drug price reductions by pharmaceutical companies.”

Once the global community invests the proper resources in research, improving TB diagnostics becomes the most critical issue. World over, governments have invested heavily in rapid and simple testing for COVID-19. The same should be done for TB, and to implement contact-tracing through mobile apps and other technology to find those critical missing millions. Lastly, it’s critical to phase out old, toxic medicines and replace them with newer, safer therapies.

Human beings are no strangers to plagues. We’ve always had them and likely always will. In a society filled with brilliant minds, hard-working doctors, and state-of-the-art technology, it is obscene to let millions of people waste away from an ancient, preventable killer. Outbreaks are inevitable but pandemics are optional.

Like the people of Oran, the fictional city in Albert Camus’ The Plague, we have no escape from history or human frailty. Perhaps the ongoing TB crisis is our road to Damascus, a once-in-a-century opportunity to build a resilient public health system that will stand strong against the inevitable outbreaks of future plague, and our penchant for inertia and division when crisis strikes.

Top image captions: A doctor listens to a patient’s lungs in City Hospital, Tuberculosis Division in Seattle, 1927 (left); A physician listens to the lungs of a woman who has fled Ukraine to Bavaria at the Gauting Lung Clinic, March 2022 (right.)

Source image credits: “Doctor and patient in City Hospital Tuberculosis Division, 1927” by Seattle Municipal Archives is licensed under CC BY 2.0 (left), and Matthias Balk / picture-alliance / dpa / AP Images (right.)

Filed Under
Black and white portrait of Vidya Krishnan
Vidya Krishnan
Krishnan is a journalist based in India. In her nonfiction debut, The Phantom Plague, she deconstructs the global tuberculosis response. Read more from Vidya Krishnan.
Mary Delaware
Mary Delaware is the art director at Harvard Public Health.

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