New Study Shows Developed Countries’ Populations at Possible Risk for TB

Read the Full Transcript

• JEFFREY BROWN:

  Here are some startling facts from the World Health Organization: Currently, one-third of the world's population is infected with the bacteria that, when activated, leads to tuberculosis. In 2003, nearly 9 million people had active TB and more than 1.7 million died as a result. As laid out in a series of studies in today's Journal of the American Medical Association, most of this devastation takes place in the developing world, especially in Africa. But there are also new concerns in the industrial countries, including the U.S.

  The Journal's editor in chief, Dr. Catherine DeAngelis, joins us now from Chicago. And with me in Washington is Dr. Paul Nunn, head of the World Health Organization's team devoted to TB, HIV and drug resistance. And welcome to both of you.

  Dr. DeAngelis, starting with you, perhaps you could give us an overview; why was it so important to devote an entire issue to TB?

• DR. CATHERINE DeANGELIS:

  Well, because I think it — when I realized how completely people in the United States, especially, had no idea about tuberculosis, and knowing that this is such a tremendous problem, it's a global issue — that I thought it was very important for us to cover this particular illness, which is devastating. I mean, when you consider a third of the world's population are infected with this bacteria, that requires a global initiative to take care of the problem.

  And I spoke with people in the United States who actually believe that tuberculosis had been eradicated from the world. When I told them some of the same figures that you just quoted, they were astounded. And the thing is, in the United States, and in most of the developed countries, the vast majority of cases that occur are from individuals born outside of the United States, and they're people who migrate to the United States. But what a lot of people don't understand is where the free travel that occurs, this can be devastating, not only to developing countries but to the developed countries.

  For example, 50 percent of the cases occur in five countries, and three of those five countries — India, Indonesia, and China — I bet most of our audience, either themselves or they know someone close by who has visited those countries, or they have had guests from those countries with whom they've had interactions; and that means they have the potential for exposure. So even if we are — even if we are chauvinistic and think completely, if you will, only about the United States, it's important. But I think it's more important for to us realize that we are citizens of the world, and that this requires the whole world. This is a global initiative that is required to take care of this problem.

• JEFFREY BROWN:

  Let me ask Dr. Nunn for a little primer for us. What exactly is TB? How is it spread? And what is the treatment?

• DR. PAUL NUNN:

  Well, tuberculosis is a bacterial infection, and you get it by breathing in air which has got droplets of bacteria in it, and those droplets get into the air by somebody with pulmonary tuberculosis, tuberculosis in the lungs, coughing out into the atmosphere, so it's– there's no protective behavior. Everybody has to breathe. So it's very easy to get.

• JEFFREY BROWN:

  And what kind of treatment is there?

• DR. PAUL NUNN:

  The treatment is with a course of four — usually four — antibiotics, which has to be taken for at least six months.

• JEFFREY BROWN:

  Now, in the developing world, is the problem the public health infrastructure, doctors, money, what?

• DR. PAUL NUNN:

  Well, it's a mixture of things. I mean, certainly, health systems and public health infrastructure is generally weaker in the developing world than it is in the industrialized world. But one of the key issues right now is in Africa, and in Africa, what's driving the TB epidemic is the HIV epidemic.

• JEFFREY BROWN:

  What's the connection? Make that for us.

• DR. PAUL NUNN:

  Well, the connection very simply is that, as Dr. DeAngelis has said, you have a third of the population affected with the TB organism. Now normally, it stays there, it lies dormant. If you get HIV infection though, HIV arrives and begins to destroy your immune system. As the immunity decrease, so the tuberculosis organisms that are there can begin to multiply, and you get the active disease.

• JEFFREY BROWN:

  So what kind of programs do you have or are there on the ground to deal with it?

• DR. PAUL NUNN:

  Virtually, every country in the world, certainly in Africa, has a national tuberculosis program, and that program will deliver the tuberculosis-control strategy recommended by the World Health Organization, which is called DOTS. And what that means is pretty well, every district — every county, if you like, in Africa — will have a district tuberculosis officer whose responsibility is to make sure that tuberculosis drugs are delivered, people are treated and the general health systems — the hospitals, the health centers — are equipped to deal with the disease.

  Now, many of them in the poorest countries are struggling. They're hanging on by the skin of their teeth, particularly since HIV has caused the numbers of TB cases to rise by five, or even up to ten times in some countries. So we have to make sure those TB-control programs are strong, and we have to link, also, with the HIV-control programs that are now being developed.

• JEFFREY BROWN:

  Dr. DeAngelis, are there some success stories around the world as well?

• DR. CATHERINE DeANGELIS:

  Well, there's a lot of success. I think the World Health Organization has done an incredible job of essentially controlling the tuberculosis from spreading even more than it has. The problem is to eradicate it. That is going to take the efforts of individuals way beyond the World Health Organization, or, rather, people helping the World Health Organization, and that means every country doing this to provide them with the resources and to assure people that we have the will to eradicate it. It is possible to do this.

  And the problem is that we're up to four drugs now, as Dr. Nunn has described. It used to be you could treat this with one drug. You can't do that anymore. And there are many of the bacilli that are now resistant to multiple drugs, and so we either continue to add more and more drugs, or we have to come up with bigger and better drugs. And we also have mechanisms that are very good for screening.

  The problem is, to try and apply these in the field, is extremely expensive or absolutely impossible to perform. The DOTS program, which is directly observed therapy, you think about, you have to stand there and watch someone take a pill, and you have to do this over a period of six weeks or eight weeks — whatever you decide is — excuse me, six or eight months, deciding what you want. That takes an incredible amount of effort. So I think that we have to realize this is a global problem. We must help the World Health Organization. That means all countries in the world need to get together and we can conquer this.

• JEFFREY BROWN:

  Now, Dr. Nunn, Dr. DeAngelis talked about the situation in the U.S., where there are many fewer cases, of course, but there's a drug-resistant strain. Tell us a little bit about what that means exactly.

• DR. PAUL NUNN:

  Well, if treatment is not properly provided to people with drugs susceptible to tuberculosis — in other words, if people take the drugs intermittently, they're not properly supervised — then drug resistance develops, and it develops drug by drug. If you get to a situation where the two main drugs, isoniazid and rifampicin, if the patient is resistant to those two, then we call it multi-drug resistance.

  Now every year, there are about 400,000 new cases of multi-drug-resistant disease occurring. The sort of epicenter of this problem is largely the former Soviet Union and Eastern European countries. But there are also — it's quite clear, there's also multi-drug resistance developing, even in the highly successful, well-organized TB-control programs that we now see in China and India, for example.

• JEFFREY BROWN:

  And to deal with this, is this where you have to be really on top of it, monitoring the therapy?

• DR. PAUL NUNN:

  Yes, you do. I mean, first of all, you need to have well-functioning laboratories that can diagnose multi-drug resistance. You need to carry out surveys so that you understand the scale, size of the problem of drug resistance. And then you need to introduce the drugs that you know will, in fact, be able to deal with that form of drug resistance. The problem is that treating multi-drug resistance is several times more expensive than treating the drug-susceptible kind. So the most important thing is prevention. In other words, treat the drug-susceptible variety properly first so that you don't form, you don't allow the multi-drug resistance to be created.

• JEFFREY BROWN:

  And, briefly, do you put a dollar number on this problem when you talk about what needs to be done globally?

• DR. PAUL NUNN:

  If you're looking at tuberculosis as a whole, we've just been reanalyzing what it would really cost in order to solve the TB problem, and we're looking at the period 2006 to 2015, when the United Nations Millennium Development Goals are due to go achieved. And one of the things that's been requested by those goals is to halve, essentially halve the burden of tuberculosis, halve the number of cases. Now, we are calculating to do that will cost somewhere around 37 billion U.S. dollars for that 10-year period. That works out to $3.7 billion per year. Right now, developing country governments are probably paying in excess of around $1 billion a year. So that leaves a gap of $2.5 billion per year, which is needed to address the whole TB problem across the board.

• JEFFREY BROWN:

  All right, Dr. Paul Nunn, and Dr. Catherine DeAngelis, thank you both very much.

• DR. PAUL NUNN:

  Thank you very much.

• DR. CATHERINE DeANGELIS:

  Thank you.