Tuberculosis remains a global threat

Host Amber Smith: Upstate Medical University in Syracuse, New York invites you to be "The Informed Patient," with the podcast that features experts from Central New York's only academic medical center. I'm your host, Amber Smith. Tuberculosis was the leading cause of death in the United States in the 20th century. And even though this bacterial infection does not kill as many people today as it used to, it remains a disease of concern. Worldwide, it's one of the leading causes of death due to infectious disease. Here to talk about diagnosis and treatment of tuberculosis is Dr. Elizabeth Harausz. She's a doctor who also has a master's of public health, and she specializes in internal medicine and infectious disease. Welcome to "The Informed Patient," Dr. Harausz.

Elizabeth Harausz, MD: Thank you.

Host Amber Smith: When I think of tuberculosis, I recall that a patient toward the end of the 1800s was likely to be sent to a tuberculosis sanitarium. Was that so the patient wouldn't infect others?

Elizabeth Harausz, MD: Yeah. So patients going to sanatoriums was probably to help prevent other people from getting infected, although truthfully, I'm not sure what understanding exactly they had back then about how the disease was spread. I mean, the organism wasn't actually discovered until the 1880s. But it was also to provide the only treatment they really had at that point, which was clean air -- the cities were very polluted at that time -- and good nutrition and rest. So really, I think when you consider all of the horrible medical treatments doctors had, that they sometimes came up with back then, I think this was actually a really good idea and really the best that could have been done for people at the time. But despite that, you know, the mortality rates were still very high.

Host Amber Smith: So clean air, rest, good nutrition. That was pretty much the treatment. That's all that they were able to do?

Elizabeth Harausz, MD: Yes. ...back then.

Host Amber Smith: Well, what happened to stop tuberculosis from being a leading cause of death?

Elizabeth Harausz, MD: There did start to be some treatments back in around the 1950s, which were still medications that are used today. Truth be told, it hasn't really advanced too much. But also just public health measures -- so improved living conditions, mostly in the United States and in Western Europe, but less crowding in city slums, better work conditions, improved health and nutrition -- all helped, contributed to tuberculosis' decline. But unfortunately recently, if you remember back in the eighties and nineties with the HIV pandemic, cases of TB increased. And TB is still a leading killer in many of the poor parts of the world where access to medical care is limited, and malnutrition and crowded, poor living conditions are still common.

Host Amber Smith: You mentioned HIV, human immunodeficiency virus. How is that connected or related to TB?

Elizabeth Harausz, MD: So, HIV doesn't kill directly. What it does is it destroys your immune system. So if there were no germs in the world, HIV would have no effect on anybody. But because it affects your immune system, it makes you unable to fight disease and more likely to get infected. And for various reasons, HIV particularly affects a part of your immune system that fights TB. And because TB can also, as we know, very much kill people with healthy immune systems, TB is also one of the first things that can kind of breach even a somewhat weakened immune system. So that's why people with HIV are a particular risk of TB.

Host Amber Smith: That makes sense.Now, before we get much further, can you tell us more about what tuberculosis is?

Elizabeth Harausz, MD: I think first, I think I should talk about the difference between latent TB and active TB, because in this country, well, actually in the whole world, latent TB is actually more common, and you're much more likely in this country to run across latent TB.

So TB is somewhat of a unique infection. Unlike most infections where you become infected and develop symptoms and then hopefully recover from the infection in a fairly rapid sequence, tB is different. So when people become infected with TB, a person's immune system walls off the organism and prevents it from spreading. And in about 90% of people, they never in their lifetime develop symptoms. They never develop disease. They're not contagious. But if they were screened for TB, with the blood or the skin test, that would be positive because their immune system knows what TB is now because it's seen it. And these tests basically just look for immune recognition of TB.

They can't tell you anything about disease or not. But so these people would never have any TB disease. And so this is what we call latent, or it's kind of, you can think of it as hibernating TB. However, in about 10% of people with normal immune systems, and more than that in people with suppressed immune systems, TB can escape the immune system's control and become active and cause disease. So that is why we treat latent TB, so it never becomes active. And why, if people are going on immune suppressive medications, like rheumatological diseases, they are screened for TB first. Um, so there's kind of two different disease states there -- latent and active TB.

Host Amber Smith: How is it spread from person to person?

Elizabeth Harausz, MD: So it's only spread by people with active TB, so people that have symptoms, respiratory symptoms. And, a person coughs the TB germs into the air and someone else breathes them in. So it's actually not spread very easily, and it usually takes close and prolonged contact. So you wouldn't get it just by like walking past somebody on the street or anything like that, or quick contact.

Host Amber Smith: What are the symptoms of tuberculosis?

Elizabeth Harausz, MD: Tuberculosis is usually a lung disease, like a pneumonia, and the classic symptoms are cough, fever, weight loss, and night sweats. And that's not just like waking up kind of warm, but it's, you know, waking up your pajamas drenched, you need to like change your pajamas. And sometimes people cough up blood as well.It's important to note that this is a chronic disease. So these symptoms start and slowly progress over weeks to months. So it's not something that you suddenly come down with over the span of, like, a week. These are prolonged symptoms.

Host Amber Smith: Does it cause lasting damage to the lungs?

Elizabeth Harausz, MD: No, not usually in this country. Here, are people that are usually diagnosed and treated quickly, and they make a full recovery.In countries where there is a lack of medical care, and people are not treated for a very long time and so they have disease for a very long time, it can cause permanent lung damage and resulting heart damage, and also particularly if they have a very suppressed immune system, tuberculosis can spread to other parts of the body. That's more rare and more seen in people who are very ill or very immune suppressed, and not what we usually see, but certainly we do see it, particularly in other countries.

Host Amber Smith: So, tB can be deadly?

Elizabeth Harausz, MD: Oh yes. So untreated TB probably has about an 80% mortality rate, active TB. And it kills, usually, by destroying the lungs. Nobody should die of TB because there are good treatments for all, essentially all forms of TB.

Host Amber Smith: Is there a vaccine available?

Elizabeth Harausz, MD: There is, but it's not a very good vaccine. It is called the BCG (Bacille Calmette-Guérin) vaccine, and it's been around a very long time, about a hundred years. It's usually given in infancy, and it does help protect young children from the worst forms of TB. So like TB meningitis and other bad forms of TB, but it doesn't protect very well, and it has a fair amount of side effects. So it's not used here in the United States anymore because its risks outweigh the benefits, but it is still widely used throughout the world where there are high rates of TB and less robust medical systems, and it is beneficial in those places. And scientists are working on to develop a better vaccine, but haven't had much success.

Host Amber Smith: This is Upstate's "The Informed Patient" podcast with your host, Amber Smith. I'm talking with Dr. Elizabeth Harausz. She's an internal medicine and infectious disease doctor at Upstate who has expertise in tuberculosis.

Now I know your research is focused on improving the diagnosis and treatment of tuberculosis. How is this disease diagnosed today?

Elizabeth Harausz, MD: Latent TB is usually diagnosed as part of routine screening. So people who may be at risk for being exposed to TB, like healthcare workers or people who are planning to go on immune suppressive medications are tested either with a blood test or a PPD, which is that little needle that they stick under your skin, and then you have to come back in a few days to see if there's a bump. If these tests are positive, and the person has no symptoms and no unusual findings on chest x-ray, then this is latent TB. For people who have active TB, so are having symptoms, TB is usually diagnosed based on symptoms. So that was a long lasting cough, fever, weight loss, or night sweats, and unusual findings on chest x-ray. If these symptoms are present, then usually phlegm is sent for a culture or PCR testing to look for the TB germ. These screening kind of blood and skin tests can also be positive in people with active TB, but those screening tests can't distinguish between active or latent TB, so in order to distinguish one from the other, symptoms and chest x-ray need to be evaluated.

Host Amber Smith: How common is tuberculosis today in the United States, and who does it mostly affect?

Elizabeth Harausz, MD: In the United States, it's not very common. So there are about 2.5 cases per a hundred thousand people every year in the United States. The rates are higher among foreign born people, compared to native born people, just because rates of TB are higher in other countries. However, lots of people who did immigrate here, as part of immigration, you're routinely screened for latent and active TB and are treated when you come. And rates can be higher among people with certain risk factors, most important factor, as we talked about, used to be HIV because it suppresses the immune system in a way that makes it particularly easy for tuberculosis to become active. But with good HIV treatments that we've had, the rates of TB among people with HIV has gone way down. And other risk factors include living in crowded settings, just because TB can spread easily if there happens to be some one there with active TB, so people who are incarcerated, people who live in homeless shelters, that sort of thing.

Host Amber Smith: What's the prognosis for someone who's diagnosed with TB today?

Elizabeth Harausz, MD: It depends where you live. In the United States, it's very good. TB is 100% curable. It's still a huge problem, though, in the rest of the world. It's actually overtaken HIV is the world's number one infectious disease killer. Actually twenty-five percent of the world has latent TB, and every year, 10 million people throughout the world become ill with tuberculosis. And despite the fact that there are good treatments, 1.5 million people die every year of TB. As I mentioned, you know, in the United States only about 2.5 cases of TB for every hundred thousand people, but in countries with high rates of TB, that's up to hundreds, hundreds of times that so 600 to 700 cases per every a hundred thousand. So a much bigger problem in other countries.

Host Amber Smith: So the treatment that's offered today, I'm assuming we have something beyond fresh air, good nutrition and rest, but are those things still prescribed?

Elizabeth Harausz, MD: Definitely. So particularly in other parts of the world, where malnutrition, especially children, is high, nutritional support is very important. This is, in fact, recommended with the WHO's guidelines for tuberculosis treatment -- the World Health Organization -- but in this country, malnutrition is not such an issue. We do have good treatments for tuberculosis, although they're all kind of relatively old. For latent TB, we do now have shorter regimens. You get either one to two medications for as short as three months, but sometimes as long as six months, depending on the medication regime that you get. And then, the vast majority of people in this country have drug susceptible TB. The treatment for that has traditionally been four medications for two months and then two medications for four months. So six months in total. But there's now actually a newly approved treatment which is only four months. And that's four medications for two months, then three medications for two months. It does take a long time to treat TB, which I think is the most difficult thing about it. The TB germ is kind of slow, and it's resting and not kind of eating a lot of the time. So it doesn't take up the antibiotic very quickly. So you need to treat for a long time to make sure you kill it. And you also need multiple medications because it can develop resistance easily. So that's why you can't just use one medication.

Host Amber Smith: Is there a concern about drug resistance?

Elizabeth Harausz, MD: Worldwide there is. In this country, not so much because we have health departments and a medical system that is very active in making sure, well, first we can test. Whenever anybody's diagnosed with tuberculosis, we always test for drug resistance, and then we have a very active health department that makes sure that people get their medications and take them. In other parts of the world, particularly in Eastern Europe and South Africa, drug resistance is a large problem. And then you have, it is more difficult to treat people. You have to have longer treatments with more difficult medications.

Host Amber Smith: Once someone recovers from TB, if they've been treated and they recover, are they protected from getting it again?

Elizabeth Harausz, MD: To a degree, but people can still get it again if they're exposed, so it's not 100%.

Host Amber Smith: Who's at greatest risk for developing TB, and is there anything that that person can do to reduce their risk?

Elizabeth Harausz, MD: So in this country, I don't think I would worry too much about contracting TB. The TB rates really are not that high. If you are in contact with someone who has active TB, the health department really does a good job of contact tracing and letting people know that they need to be evaluated. And people in high risk jobs are usually routinely screened through their work. But I would say if people are having chronic longer breathing issues, you know, unfortunately there are a lot worse things than TB that it could be. So they should definitely contact their doctor to let them know. But I just would want to say that one of the reasons that the rates of TB in this country are so low is that traditionally we've had a very strong public health system. It does provide a lot of services and works very hard to trace and treat contagious diseases, to the benefit of us all. Unfortunately, during the COVID pandemic, we have seen that our public health system is under stress due to underfunding. It's not an accident in this country that most of us, for most of our lives have not had to worry about contracting a contagious disease during our daily activities, and we have our public health systems to thank for that. And it is really important that we continue to support them and fund them.

Host Amber Smith: Well, Dr. Harausz, this has been very informative. I thank you so much for your time.

Elizabeth Harausz, MD: Yeah, thank you very much. Appreciate it.

Host Amber Smith: My guest has been Dr. Elizabeth Harausz. She specializes in internal medicine and infectious disease at Upstate. "The Informed Patient" is a podcast covering health, science and medicine brought to you by Upstate Medical University in Syracuse, New York, and produced by Jim Howe. Find our archive of previous episodes at upstate.edu/Informed. This is your host, Amber Smith, thanking you for listening.