March 24th marks World TB Day, 135 years since the Mycobacterium tuberculosis bacteria was discovered, so now is a particularly good time to take stock of the progress—or lack thereof—that we've made in battle against this disease. And let's be clear: We're not winning. After two decades of decreasing numbers of cases, a new report from the CDC shows that the rate of active TB infections in the US has leveled off to about 2.9 cases per 100,000. Though 2016 recorded the lowest number of new TB cases in US history, at 9,287, the overall population rate has stayed virtually the same. Experts warn that unless the rate of decline picks back up, US TB elimination won't happen in this century.There are also currently millions of cases of latent TB in the US—cases that aren't infectious and don't have any symptoms, but which might bloom into an active infection when the host's immune system is compromised, maybe as the result of another disease or just old age. The vast "reservoir" of these latent cases and the rise of multi-drug resistant and extremely-drug resistant TB overseas pose very real threats to Americans. The current upward trend frustrates American TB advocates, a small but passionate group that often feels painfully unheard. Our complacency, they warn, could lead to the next large tuberculosis outbreak. There's a saying this community has, when it comes to the state of TB in America: Tuberculosis, they say, is "forgotten, but not gone."There are millions of cases of latent TB in the US, which might bloom into an active infection when the host's immune system is compromised.
It's hard, though, to care about something if you don't know it's a problem. Unfortunately, TB advocacy in the United States is nearly invisible. Before she went on a trip to Zimbabwe, Liz Stapf, an American student from Oregon who traveled to volunteer at an orphanage in 2008, didn't know that she was at risk for TB. She had the common misconception that you could only get TB if you were HIV positive; so when she lived with a young boy infected with active TB for several months, she felt perfectly safe.One night, Stapf sat up in bed and began to cough as liquid pooled in her lungs and rose into her mouth. She flicked on a flashlight: her clothes, her bed and her mosquito netting were covered with blood.
Advocates like Stapf and Rugg wish there were more public awareness about TB, not only so more people would get tested, but because funding is crucial, too. In February 2016, President Barack Obama asked Congress for $1.9 billion to combat Zika, a disease that has been linked to two deaths in the continental United States. Meanwhile, funding for tuberculosis, which caused 493 US deaths in 2015, has continued to decrease. In 2015, funding dropped to $6.2 million, the lowest in the past seven years. Yet economically it makes sense to fund TB: Researchers have shown that if TB funding and elimination goals had been met in 2014, the United States would have saved $420 million dollars for that year alone—not to mention hundreds of human lives.Obama asked Congress for $1.9 billion to combat Zika, a disease that has been linked to two deaths in the continental United States. Funding for tuberculosis, which caused 493 deaths in 2015, dropped to $6.2 million, the lowest in the past seven years.
Most doctors and scientists aren't concerned about the current rate of TB in America, but they are growing increasingly worried about the future. Despite the disease causing several hundred deaths a year, most Americans are unlikely come in contact with TB in their daily lives—and if they do, we have an arduous, but effective, treatment."I think the general public shouldn't be too worried about TB," says John Balmes, a doctor at UCSF who specializes in lung research. But, he adds, "I think the general public should be worried about the reservoir of TB that is in major cities." In California alone, it is estimated that there are over two million people with the latent infection (that's what Balmes means by "the reservoir"). Many of these people will never feel symptoms and can't pass it along while it stays latent, but about 10 percent will get the active disease. Since TB is a disease that capitalizes on a weak immune system, doctors worry about cases of chronic immune-compromising diseases like diabetes rising among the American public, subsequently making more people vulnerable to TB. They also fear a major resurgence of tuberculosis could occur should another epidemic like HIV or the H1N1 flu come around.The second source of concern is the slow but steady rise of multi-drug resistant TB (MDR TB) and extremely-drug resistant TB (XDR TB). XDR TB is resistant to the two most potent TB drugs, isoniazid and rifampin, and only about 30 to 50 percent of cases of XDR TB are cured.Unlike Balmes, Zuroweste believes that tuberculosis is a disease that all Americans should be concerned about. "MDR/XDR could cause mass casualties in the United States," he says. Since we live in a world where crossing borders is almost effortless, we will continue to get cases of TB here in America unless it is fully eradicated worldwide. This is possible, says Zuroweste, but it will be difficult. "It could be stopped," he says. "All it takes is political will, and financial resources."In California alone, over two million people have the latent infection. About 10 percent will get the active disease.