From the Special Topic of
According to our Special Topics analysis on
tuberculosis (TB) research over the past decade, the work
of Dr. Mario Raviglione ranks at #9 by total citations and
#7 by citations per paper, based on 49 papers cited a total
of 3,593 times. Three of these papers are also on the list
of the most-cited papers in this topic. In
Essential Science IndicatorsSM from
Reuters, Dr. Raviglione's work can be found in the
field of Clinical Medicine.
Dr. Raviglione is the Director of the Stop TB
Department of the World Health Organization, a position he
has held since 2003. He is also the recipient of the
Princess Chichibu TB Global Award from the Japan Anti-TB
In the interview below,
ScienceWatch.com correspondent Gary Taubes talks with Dr.
Raviglione about his highly cited work on TB.
Your most-cited article in our analysis is a
1999 JAMA paper on the global burden of TB (Dye C, et
al., "Global burden of
tuberculosis—estimated incidence, prevalence,
and mortality by country," JAMA
282: 677-86, 18 August 1999). Do you consider this
to be your most significant contribution to TB research?
Actually, a JAMA paper I wrote in 1995 may be in its way more
important. I wrote this earlier paper with Dixie Snider, who was at the CDC
at the time, and Arata Kochi, who was director of the TB program at WHO.
The 1995 paper was called "Global epidemiology of
tuberculosis—morbidity and mortality of a worldwide epidemic,"
(Raviglione MC, Snider DE, Kochi A, JAMA 273: 220-6, 18 January
1995) and it was actually what turned our knowledge of TB around. It is the
one that, more than any other paper before, announced to the world the
global problem of TB and that of multidrug-resistant TB and it did so by
being in a highly visible journal like JAMA. That paper was among
the most-cited papers I have—it's still cited today—and it
ended up in the New York Times, making the global TB situation
better known to the wide public
You have to realize that at that time the management was really not keen
about the idea of having WHO staff publishing peer-reviewed papers. This
paper actually changed the environment. The debate at the time in WHO was
whether we should write peer-reviewed papers for scientific journals as
though we were academic experts, or should we merely be officers who do
administration and simply convene other experts who write the papers. Even
in the TB program this debate was going on. Is it cost effective for WHO
staff to work as though they're academicians writing peer-reviewed
A field visit in Swaziland, at the tent of a MDR-TB
patient living in the bush and attended by a
When that JAMA paper came out in 1995, it made people understand
the importance of scientific communication. We all realized that by writing
a scientific paper like that and getting it published in a journal like
JAMA we could get to the front page of the New York Times
and people would suddenly pay attention to the problem we were discussing.
It was far more effective than, for instance, paying hundreds of thousands
of dollars to do advocacy and communications based on anything rather than
science. The realization was quite clear that if we publish in highly
visible journals like JAMA, we get the advocacy and communication
free of charge, in a way, by getting directly to the front page of major
newspapers. That was a very important understanding. At that point we
really started targeting more and more visible journals any time we had an
important paper or an important topic to discuss and disseminate.
What prompted you to start calculating the global
burden of TB as you did in the 1999 JAMA paper?
This was actually a repeat of an exercise we also did a few years earlier,
which we also published. The earlier one had a less complex methodology,
but it was the first to use a simple mathematical model to assess the
global burden of TB, in the sense of global estimates of TB morbidity and
mortality, the association between TB and
HIV/AIDS, and so forth. Our intention was to
communicate widely about the burden of TB in the world.
We repeated this exercise again in the 1999 JAMA paper, and then
again every two to three years. On those papers I worked primarily with our
team previously headed by
Chris Dye, who is a
mathematical modeler and epidemiologist. That team has done a huge amount
of work on the TB epidemic, using the statistics and data we receive and
putting them into a mathematical model that can derive quite important
conclusions about how we might handle the TB problem.
Can you tell us how the model and its conclusions
influence your actions at WHO?
Before making policies about intervention we often, if not always, study
the potential implication and impact on the TB burden. Let’s say we
have two or three interventions we could use. These models tell us which is
likely to be the most cost effective. If we do this particular prophylaxis
or treatment, for example, how much TB is it going to be cut in the next,
say, 10 or 20 years? Then we can apply cost-effective analysis and economic
analysis to these epidemiological exercises and projections. Now we can say
not only will this intervention cut the number of deaths by x percent, but
it will eventually cut costs by y percent. This kind of analysis is now
done regularly in our program.
How has the state of our knowledge about TB
evolved in the last decade?
First of all we have better understanding of the disease epidemiology. The
more we improve surveillance methods in countries, the more data we
collect, the more countries themselves improve and report on TB, the better
we get in terms of estimating the global burden. So now we’re more
confident about the quality of what we’re saying.
What we can conclude now, from a number of different exercises, is a
consistent number—about 9 million cases of TB a year, and 1.7 million
deaths. We’ve also seen that the TB epidemic may have actually peaked
in 2004. The absolute numbers might give the impression that it is still
growing or is being stagnant, but that’s because population growth is
more rapid than the decline in rate per capita. What we think today is that
rate per capita may be coming down all over the world, even if the absolute
number of cases keeps growing, although very slowly.
By mid-January 2009, we finished our latest assessment, and this is still
the feeling we have, as we said in our latest Global Report published in
March 2009. That’s a big difference from earlier in the decade, and
we think it's due to the expansion worldwide of TB prevention practices. As
a consequence we may now actually be seeing some impact in the actual
burden of disease.
What is the most challenging aspect of doing this
kind of global TB epidemiology that you’ve been doing at
In a way, as the person responsible for the global TB program, the most
important and challenging thing is to be constantly up to speed with the
literature and where the science is moving. In other words, as director of
the WHO program, I'm not just a manager; I'm directing a huge operation and
must study the technical and strategic directions. The direction itself is
what we announced in a Lancet paper in 2006 when we presented the
new Stop TB Strategy, but I still have to keep up with the literature to
allow us to adjust, innovate, and change direction appropriately as new
The latest challenge, for example, is XDR-TB—extensively
drug-resistant tuberculosis, which is just what it sounds like. The first
description of XDR-TB was in March 2006. Since then, there has been a
mushrooming of papers about XDR-TB all over the world. This is the latest
challenge, and we have to be on top of it—we have to be at the
forefront when it comes to global policies, surveillance, data analysis,
and so on.
"In the global village that we now
live in, we can’t stop TB at the
It's also critical for us here to maintain a certain level of credibility
in our research, because we’re not in academia but we want our work
to be taken seriously and have the necessary impact. If you look at your
list of the top 20 authors in TB, you’ll find that Chris Dye, myself,
and maybe one more are the only ones not formally involved in academia and
basic research. Most of the most highly cited papers are on very basic
research, and most of the authors do basic research. So in WHO, getting
back to this point, we have to maintain the credibility of our program and
the people working here, and one way to do that is to be active in the
What would you like to convey to the general
public about your work?
Well, the big issue is that TB is a major disease, second only to HIV/AIDS
in terms of the number of deaths a year from a single infectious agent. TB
kills over 5,000 people a day; 1.77 million a year. That’s an
enormous number of people. Now consider how much press is given to avian
flu, for instance, which might have killed 200 people so far. Or even
SARS, which killed a bit more than 1,000 people
altogether—or less than a fourth of what TB kills on a single day.
The problem of TB is not often seen from this perspective. There are
people who say that if SARS struck again today and killed 4,000 people,
you'd have a public health revolution in the world with all leaders in
the forefront to mobilize money and resources. For TB, only very few
care. Humanity has been living with TB for a millennia. It’s not a
story. Why bother? That’s exactly the attitude we're facing all
the time. Let alone the sense that TB is a disease of the past and that
is extinct in this world. This is a constant question by media when they
discover that it kills in the South as in the North, today, we all our
advances in medicine and the availability of a curative treatment.
You can call this neglect, denial, whatever you like. The reality is that
TB mortality comes in just after that for HIV/AIDS, but the threat of
HIV/AIDS receives much more prominence in decision-making environments than
TB does. This is something we cannot accept. That's why in the last two
years, we've been pushing the agenda, trying to involve personalities and
celebrities, so we can make a better case for paying attention to TB. Thus,
the big message is be aware that TB is around, and it's still killing
everywhere. Not a single country in the world has eliminated it, and it
kills 5,000 people a day. Now we're facing the challenge of these extremely
drug-resistant forms that do not respond to conventional anti-TB drugs or
even the anti-TB drugs we have in reserve. If we don’t act, if
countries don’t move now, we will let the epidemic continue, there
will be more resistant forms spread, and TB will continue to kill.
The last point is that TB is not just a disease of Africa, Latin America,
or Asia. It's a disease of the whole world. In the global village that we
now live in, we can’t stop TB at the border. The disease is
transmitted by a cough and a breath. The point is that no one should feel
safe; it can come to our door anytime. Thus, we need to act assertively and
invest what is necessary to fight it back, while supporting more research
to get better tools than we have today.
Dr. Mario Raviglione
Stop TB Department
World Health Organization
KEYWORDS: TUBERCULOSIS, GLOBAL BURDEN, EPIDEMIOLOGY,
MORBIDITY, MORTALITY, HIV/AIDS, SURVEILLANCE METHODS, TB PREVENTION