The world's deadliest pandemic is on the rise in the United States

We discovered the cause 144 years ago.It's still a big problem.

Something unusual happened at Archbishop Riordan High School last fall.

The world's deadliest infectious disease is on the rise in the United States

We discovered the cause 144 years ago.It's still a huge problem.

In September, a student at a Bay Area school visited a health care provider because of a cough that wouldn't go away.But less than two months later, the student was diagnosed with tuberculosis.The San Francisco Department of Public Health (SFDPH) launched an investigation that revealed a surprisingly high rate of latent tuberculosis — meaning people have been infected with the bacterium Mycobacterium tuberculosis, but their infection has not yet progressed to an active, contagious disease — at the school

As of February 24, the latest data available, there are four confirmed active TB cases in the school community and an additional three active cases suspected by the Department of Public Health.

A private school in San Francisco is not where you'd expect a case of tuberculosis to occur.TB is a disease of poverty and racism, but today the developing world bears the greatest burden.The majority of all new cases (about 87 percent) occur only in 30 low- and middle-income countries.

But it used to be common in the world.Turn back the clock: On March 24, 1882, German doctor Robert Koch announced that he had discovered the cause of the disease that killed one in seven people in America and Europe.Fast forward to now: Today is World Tuberculosis Day, the 144th anniversary of Koch's discovery.And the disease is coming back in rich countries.

The diet has been called the "thief of youth" - the white plague - but it certainly cannot be said that it no longer exists.And although it was quickly overtaken by Covid-19, in 2023 tuberculosis regained its status as the leading cause of death among infectious diseases in the world.It infects around 10 million people each year and kills 1.5 million - although it can be prevented and treated.Counting latent and active cases, the virus may affect a quarter of the world's population.

"The global is local and the local is global, so if we can't deal with the global burden of tuberculosis, we will continue to see it everywhere," Priya Shit, professor of medicine and tuberculosis researcher at the University of California, San Francisco, told me."We're going to start seeing TB emerge in the least expected places."

The United States has the infrastructure for tuberculosis testing and treatment, and it is not currently endemic here.Like much of the world, however, it used to be—it may have killed as many as a quarter of all Americans in parts of the 18th and 19th centuries.But improvements in nutrition, living conditions, sanitation, and especially the advent of antibiotics in the middle of the 20th century changed things dramatically.However, "not endemic" is far from "eradicated".

Tuberculosis rates in the US are increasing after 30 years of decline.In February, it emerged from an American high school in the Bay Area, with confirmed cases in Long Island, New York and Seattle.One of the largest outbreaks in the US since the Centers for Disease Control and Prevention began reporting TB cases in the 1950s occurred two years ago in Kansas, with 68 active cases.cases, there were 91 latent infections and two deaths.

Extensive investment in public health infrastructure, shortages in drug supplies, delays in diagnosis due to the spread of Covid, and challenges in detecting and treating latent cases are part of why TB remains a disease of concern in the United States.

This year's World Tuberculosis Day theme is "Yes! We Can End TB!"That is very ambitious, given that it is still an ongoing challenge even in the richest countries in the world.Its persistence requires us to stay ahead of the evolutionary arms race with the pathogen, which may have been on Earth for 3 million years.But there is hope - advocates are pushing for continued investment in tuberculosis research and fighting back funding cuts, and scientists are working to develop new treatments for this very old disease.

America Against Tuberculosis

Tuberculosis is spread through the air, and you don't need to cough to infect someone else – regular breathing can do the trick."There is no TB-eradicated or TB-free country in the world," Lucica Ditiu, a doctor and executive director of the Stop TB Partnership, told me."As long as we breathe, we are all vulnerable."

About 13 million people in the United States have latent TB, which progresses to active disease in 5 to 15 percent of cases when left untreated.Tuberculosis preventive treatment (TPT) for occult cases can clear the infection in three months with appropriate antibiotics, but lack of access to these drugs or delays in diagnosis often prevent patients from starting TPT.

If left untreated, a person with active TB can infect 15 people a year.

Latent infections become active when the immune system can no longer prevent the bacteria.Infants, young children, the elderly, and immunocompromised individuals are at greatest risk of transitioning from latent to active disease.Our health is not always in the course of our lives: "You can have latent TB throughout your life, and in your last chapter ... if your immune system is suppressed, it can become active and you can start spreading it," RC Sadoff, a public health researcher at Johns Hopkins University and a member of the Zero TB Children's team, which screens children in and around South Asia for TB.spaces in school monasteries."There's dust everywhere."

If left untreated, someone with active tuberculosis can infect 15 people a year.In the United States, more than 80% of cases result from latent cases becoming active.To complicate matters, the difference between latent (and non-infectious) and active (and contagious) tuberculosis may not be binary, but rather a continuum.It is not always clear at what point someone becomes infectious, and people can be contagious without the traditional symptoms of tuberculosis.One study estimates that subclinical cases – active infection but no symptoms – are responsible for 68 percent of tuberculosis transmission worldwide.

“I think it's likely that at least some of the latent TB that we're seeing [in the Archbishop Riordan High School community] could have been transmitted by people who don't have symptoms but still have TB,” Sadoff said.

Compared to a disease like cancer, cancer is more common.The main symptom people usually have is a constant cough.

"It's diagnosed as not being tuberculosis and it persists for a long time. So the risk with tuberculosis is that it can look and act like a lot of other things that aren't that bad," Shete said.When people experience night sweats, another common symptom of tuberculosis, they are more likely to think it's hot flashes rather than tuberculosis, she said.“Thinking about tuberculosis requires a little more vigilance.”

Delays in TB diagnosis have been exacerbated by Covid, and the effects have not been reversed.Today, new TB patients are often much sicker at the time of their diagnosis than they were before the epidemic.Delays in diagnosis and treatment mean more time for disease to spread unchecked, more opportunity for bacteria to develop resistance to antibiotics, and more avoidable suffering.Successful treatment of TB requires months following a schedule of multiple antibiotics to prevent the bacteria from developing drug resistance.

The delay in TB diagnosis was exacerbated by Covid and this effect has not yet been overcome.

Another major obstacle to fighting the disease in the US is cost.According to the California Department of Public Health, TPT for latent tuberculosis can cost a single patient about $857 for three to four months of treatment.The diagnosis and treatment of active tuberculosis patients costs more than 50 times.If TB and multidrug-resistant TB in the US reach the current global average, the cost of treating TB cases in the US will increase by more than $11 billion per year.

Funding cuts to programs like USAID's could result in 2.2 million TB deaths in 26 high-burden countries between 2025 and 2030. Drug-resistant cases could increase by 30 percent, requiring drugs that are difficult to use and not FDA-approved in the US.

In the United States, the disease often spreads in places where there is not enough health care to diagnose people with active TB and in crowded places, with poor air quality and high levels of malnutrition, such as prisons and shelters.As in other regions of the world, the most vulnerable in the US are at the highest risk - and the most difficult to treat.

"A weak health care system in a high-income country takes the brunt of a TB epidemic," Sadaf told me."Anytime there is a TB epidemic in the United States, something is wrong.

Prevent the spread of tuberculosis in the United States and beyond

At Archbishop Riordan High School, 207 members of the school community have tested positive for latent tuberculosis.To return to in-person teaching, students had to share test results, what treatment they were on and how long they had been taking the medication, but they didn't have to test negative for the bacteria.According to the grandparents of a late TB student who spoke to me anonymously for fear of retribution from the school.

About 80 percent of students with latent TB were on TPT as of Feb. 24. The school does not legally require students with latent TB to receive the drug — which can prevent the infection from developing into active disease.Still, Patty said the school has decided not to continue offering online learning options to untreated students: "To me, it's not about containing it or preventing the spread."

Archbishop Riordan High School did not respond to multiple requests for comment on the policy or other questions specific to the outbreak.All people confirmed or suspected of having active tuberculosis are under treatment and are no longer considered contagious, according to the latest of the "TB Town Hall" webinars held for the school community.

"Individuals with latent tuberculosis infection (LTBI) are allowed on campus because LTBI is not contagious," the San Francisco Department of Health said in an email to me.It "strongly recommends that all people with LTBI begin and complete treatment, and we will continue to educate the community about its importance in preventing future illness."If someone tests positive for TB, even after successful treatment, the test remains positive indefinitely, making diagnosis and follow-up difficult: people who have recovered can become infected again.

The story of Archbishop Riordan High School shows how the control of anything is a complex and contested development.Wherever TB occurs, ensuring a community is safe is difficult.This is the main reason for protecting the key.

Health officials from the Department of Public Health emphasize that the risk to the general public is low, and currently we are not seeing many outbreaks in the US.But the further destruction of American public health infrastructure and research funding affects our ability to reduce the impact of this disease.

If you want to do something about this global threat, you can donate to Stop TB Partnership, TB Alliance, The Global Fund, Partners in Health, and Spiro, which provides testing and TPT for children in Pakistan, a country with a very high rate of this disease.You can be a TBFighter, part of author John Green's team to tackle the causes of tuberculosis.You can also become a member of Stop TB USA, which makes it easy to connect with your representative to support continued funding for public health.They also accept donations.

Advocating for the development of new drugs, better diagnostics, vaccines to protect adults, and continued investment in TB research, prevention, and treatment are the most powerful tools to end TB in the United States and beyond.Even if it doesn't happen until next year's World TB Day.