Public Health Threats, Challenges and Triumphs in Asia
Remarks at the Asia Society Hong Kong Center Luncheon

Dr. Barry Bloom
Dean, Harvard School of Public Health

Speech and Q & A session.

Hong Kong, September 26, 2003

I thank the Asia Society and this distinguished audience for taking the time to come.

Let me begin by setting a context for public health in the broader sense. We live in a world where there are 1.2 billion people who live on less than $1.00 a day, and almost half the population of the planet lives on less than $2.00 a day. We live in a world where the disparity between rich and poor countries has increased since 1970, so it is now ten times greater. We live in a world where one in six kids goes hungry.

If one looks at the growth of population, we add 200,000 people every day. But I think an interesting and important fact - in almost 70 countries - more than 40 per cent of the population is under the age of 15. We are faced with a whole new world of teenagers and their education and their security is not assured.

The environment as we think about public health is changing dramatically. I came upon the figure that half of China's cities now face water shortages and, at the same time, sea levels over the last century have risen about 4 to 8 inches, and will continue to do so. Many islands will simply disappear in Polynesia. Temperature is going to rise as a consequence in the next century. The rain forests are going to be gone, or on the way out. Many species will be extinct, and this means that many insect borne diseases will change their habitats, moving like malaria is now, into cities, and we will have to face things that we have not in cities for maybe 50 years.

In civil society we cannot forget the fact that the world is not an orderly place. There are at least 31 civil and foreign wars and about 35 million to 45 million displaced persons who have a tremendous proclivity for beginning and starting epidemic infections.

Let me start with a kind of overview from someone who lives in a world where not everybody appreciates what we do and what the importance of public health is. The standard economic model taught in all business schools, and probably all universities, is that if you get the macro economics of a country right, health will follow. In fact, that turns out not to be true.

Since 1993, when the World Bank first looked at the value to economies of investing in health, there has been a new school of economics that indicates, no question, macro economics in getting the economy strong has a huge possibility for increasing quality of life and health. But, on the other side, there are major opportunities by investing in health. For the first time, the bank saw this, that created tremendous amounts of economic gain. The failure to invest in health, as you now know from the SARS epidemic, can have tremendous economic costs.

What is the impact of infectious diseases and other kinds of ill health on the economic growth of a country?

We know, obviously, that reduced years of healthy life expectancy, reduced productivity, and that is exacerbated by early death and chronic illness, which are costs to the system and deplete the productive force.

We also know that you cannot run businesses -- we know in, for example, South Africa, that people hire two managers for each job in many big industries because one of them is going to be dead from AIDS in 10 years. It is very hard then not to have industries, large corporations functioning, let alone the social co-operation needed when we have now 10 million orphans from HIV. There is a question of political stability in many countries. What will we do with these kids when they become teenagers?

Finally, in the tragic case, one of the responses to ill health is to have lots and lots of babies. So the poorest countries and the poorest people end up with the most children, that they have the least ability to give good quality of life and education.

Now, I am going to refer a little bit in the talk to how do you measure the burdens of disease that countries face. Obviously, the most accurate figure in almost every country in the world is the number of people who die. But in addition, lots of people suffer from chronic diseases and continuing illnesses that remove the complete health quality of life. This is called disability adjusted life years. How many years of healthy life are reduced because of a disease?

Then, if one wants to globalize that and say: how does that translate into economic loss to a country, which is mostly all that politicians care about, then you can simply multiply the number of lost healthy life years by a multiple of the per capita income. In the western societies and countries, usually that is taken to be a multiple of three, so that everybody who dies not only loses their own per capita income but ultimately, over the projected loss of life, impacts to X what they would ordinarily if they were alive.

What are the global burdens of disease? What do we suffer from? Where do we lose healthy years of life?

From 1996 on, for the first time, deaths from non-communicable diseases exceed those from infectious diseases. The rare exception, as you will see in a moment, is in the continent and sub-Saharan Africa. In terms of the burden of illness, healthy years of life loss, it is about equally split now, according to WHO, between infectious diseases and non-communicable diseases.

The third point of this, quite surprising to everyone, and I should say these studies were really begun at the Harvard School of Public Health by Christopher Murray, who then went to WHO to lead their health policy group and is now returning to Harvard. This is the first time that anybody knew what people died of in the 191 countries of the world.

One of the most rapid causes of burden of disease are automobile accidents and that is the 14 per cent in the lower column.

So if we look now to get closer to the issues at hand in Hong Kong, to the global burden of infectious and perinatal disease, it represents about 32 per cent of the global total, 43 per cent of the disability adjusted life years. But in Africa, two-thirds of deaths are still caused by infectious diseases. In South East Asia it is about 37 per cent, at least according to WHO in 2001. A major burden. We call this the unfinished agenda in health. We should be able to reduce this to a very much smaller level, and we have not done a good job of doing that.

Clearly, as children do not die, we have an increasing burden of chronic disease where if kids do not die when they are young, they then develop heart disease, strokes, diabetes, and that is the coming epidemic of an aging population and a new set of diseases which are going to be very hard for developing countries to address.

I want to talk about three diseases. One, not because I work on tuberculosis, but it is a really good introduction to how we know a lot more about TB than we do about AIDS, and perhaps a way we could think about it. Second, the major global health problem in communicable diseases is HIV and AIDS, and then a little bit about SARS.

The first question is, is SARS an anomaly, is AIDS an anomaly? This is just a list of some of the 32 new diseases of humans that have been identified since 1970. None of these diseases, which we are all now familiar with, was recognized before 1970. So what this says is that there is a continuing evolution of the interaction between animals, which may be reservoirs for these diseases, and humans. As forests are taken down, as the environment changes, temperature and water change so that this is not something that anyone should be surprised about.

We know that at least in the last 30 years there have been major outbreaks in epidemic diseases that have not been previously described. Is this an epidemic of the press or is this real? And so, for a little historical note, if you go back to the earliest reference on communicable diseases, which you will see in a moment, that my wife dug up for me from one of her books, the first representation of an infectious epidemic was in 610 in China. Then, as you can see, there is recorded history of emerging infections long before 1970. So this is not an epidemic of the press; this is something that every society has to anticipate and expect because it will continue.

The report that I referred to, really the first report ever of contagion -- and I should say that the first western reference was in the early 15th century by Fracascardi. It goes, as you can you see, that warm disorders, which are fevers, are caused by disharmony in the seasonal phenomena and when this happens people respond to perverse and violent numetas(?), whatever they are, winds and breathing on each other, by becoming ill.

The key sentence is, "The pathologic qi moves on to infect others, even to the point of wiping out a family and spreading outside of it." Pretty accurate description of SARS.

This is why respiratory infections are so challenging. This is not a cough. This is a man saying the letter S in front of a camera. The first point to recognize is, as you know, not only is SARS carried by respiratory transmission, but tuberculosis is. What I can say is, what you can see in the photograph are not the particles that transmit the infection. Multiply those by 10,000 smaller particles that you cannot see, and that is what you breathe in and gets into the lung. If there was a cough it would obliterate the photograph.

The first point is respiratory infections are very dangerous and historically have really very seldom ever been controlled with the absence of treatment. The second is that tuberculosis is, in a sense, a co-epidemic with HIV. This is the percentage of people who come to a TB clinic in Africa that are found to have HIV. The fact of the matter is that virtually 70 per cent of people who have HIV and, as you will see, 32 per cent of people who die from AIDS in Africa are actually dying of tuberculosis as the attributable cause of death.

TB has almost 9 million new cases a year but the good news is that most of them are in only 23 countries. So the world could focus its attention and really wipe this disease out if they really got their public health and treatments right in these countries. TB causes 2 million deaths and I should say, since you can only die once, all TB deaths in HIV positive patients are scored up as AIDS deaths. So you could actually add another million to this and really get the number of actual TB deaths.

A third of the world's population is tuberculin skin test positive, which means has been infected with TB, and if they become immuno-deficient by HIV infection or aging, are subject to re-activation of their disease. If TB is not treated, 50 per cent of people die.

The most frightening thing in this realm is the fact that by poor treatment, which in some senses is worse than no treatment, there has emerged the development of multi-drug resistant TB, resistant to the best drugs we have and for which the only available drugs are not very effective and very, very expensive. And there are states in Russia, for example, where everybody has drug resistant tuberculosis.

The importance of mentioning TB is that we actually know a lot about it and we know how to cure it. We know that three to four drugs given for six months, either every day or a couple of times a week, at a cost for the total treatment of $8.00 to $16.00 per patient, will cure 90 per cent to 95 per cent of the cases. We know that it does not even have to be administered by doctors, that in poor countries one can have community people observing people taking their pills. The only important thing here is to have the medicines available and see that people take it every day. If they take it every day they do not get resistance. If they do not, if they take the pink one today, and the blue one tomorrow, and "I don't feel good on Thursday", that is when multi-drug resistance occurs.

For a long time WHO recommended a mixture of regimens that were graded by their price. The World Bank showed a very important thing: the cheapest drugs are not always the most cost-effective drugs. It turns out the best drugs are the most expensive and yet they are most cost-effective because they are most effective. That, once you know that, creates a market that reduces the price, in my experience, from $125.00 per case to $8.00 per case in some countries.

What are the economics of TB? How big a burden is it?

We know that of the 8.7 million, if we assume they lose about 30 per cent of their income and 2 million die and, we say, die on average 15 years before they should have died, and you throw in all the money that countries spend on diagnosis and treatment, the financial burden on the world is about $16 billion.

WHO estimates that if those 23 countries would invest less than a billion dollars a year, they would reduce deaths by 50 per cent. They would cure 22 million people, they would avert 16 million deaths, and gain for their economies a return of $6 billion. That is a pretty good investment.

Let me now turn to the other major problem that you know as well as I, and that is HIV infection. Let me start with a success story which is Thailand.

The red line is the accumulated number of infectious cases that have accumulated since 1985 when records were kept. The first point is that the green line shows the rate at which new cases appear. The extraordinary thing about Thailand, as you will see momentarily, is that it took a few years to realize that this was a very bad infectious disease and they implemented public health measures, massive government supported education programs, and they reduced the incidence to relatively low levels.

Nonetheless, everybody who was infected stays alive for, on average, eight to ten years, and can spread the disease. So the prevalence of infection, even in Thailand, which is the poster boy of countries, is actually relatively high.

What about China? We know that there is a volcano or an iceberg of which the tip is only visible now. We know that in many places -- Henan, for example -- for contamination of blood, sex workers in several states where they have been able to be surveyed by China's national AIDS program, the rates are increasing at an alarming rate. You have to understand that there is a 10-year lag between people dying of HIV and having it register on the consciousness, and the time they get infection, which means, if you want to stop dreadful things happening 10 years out, you have got to act now.

This is HIV prevalence in blood donations, mixing bloods, small numbers of sick people or infected people with lots of others. It is a very efficient way of spreading any infection.

I think the most shocking slide I am going to show you is this now. If you look at HIV prevalence in Thailand and South Africa, in 1990 and 1991, the rates of prevalence of HIV infection were almost indistinguishable. Thailand made a major national effort to control and, as you can see in the pink line, it kept the rates of HIV down to a remarkable extent, even though the tools we have are terrible.

South Africa chose not to do that and in fact to deny that there was a virus that caused AIDS, and now they are up to 25 to 28 per cent of the young people that are tested as being positive. The highest in the world is Botswana where 42 per cent of pregnant women are HIV positive. If they do not get drugs they are going to die and produce orphans.

Now, to what extent is knowledge empowering? The question is, do people get AIDS because they do not know how to prevent it, or protect themselves? An important study of what drives HIV in Asia tested sex workers in Indonesia. The top two curves show awareness, "Do you know that HIV is causing AIDS and that condoms protect?" is known by 70-some per cent of the population. "Do you use them?" -- by almost less than 10 per cent. There is a huge gap between knowledge and action and we have to move to close that gap.

We also know that even if one does it well, as in Thailand, that, if, at any time, one drops one's guard, stops the promotion and the education programs, and we go from 85 per cent condom use to 60 per cent, the epidemic takes off again. This is a long-term constant battle to keep this infection under control which, to a large extent, has not really yet been engaged by China.

In the worst case, there is a sense that, well, there will be drugs for this some day. In fact, we have good drugs now. Those drugs have reduced deaths from AIDS in the United States by 75 per cent. They turn out to be very expensive, moderately toxic and very hard to administer in a continuing basis in any populations.

This is a model of what would happen in India if drug treatment were used and the top curves on your left show very high rates of drug resistance if, under present circumstances, the drugs were made available to the general population. On the lower curves, still high rates but much lower if they are targeted to sexually active sex workers, highly targeted programs.

What it says is drugs are not a panacea and that this is life long treatment, not six months treatment, like TB. I have frankly to admit that nobody really knows how to do it in poor countries and communities. We have to learn and we hope to be able to learn from the reduced cost of drugs by the drug companies, starting in Africa and Thailand.

The economic burdens of AIDS are tremendous if you take disability adjusted life years. It turns out if you value a life year in terms of one X per capita income, if somebody is taken out of the economy that would be about an 11 or 12 per cent reduction in GDP. If you do it in the standard western calculation of one life productivity direct and indirect, is about 3X one per capita income. Then the loss in African countries of about a third of their entire GDP is now being consumed by the losses of productive people that have HIV.

There are projections of three scenarios in China and India. What would happen if the epidemic is intermediate and kept under moderate control or is severe? As you can see, the expectations for China would be a very significant, almost 25 per cent by 2025, reduction in the productive work force, which would be devastating for any economy, particularly economies that become more knowledge based and have investments made in them. It is a very serious issue.

What are the returns on investments in prevention, which is what public health is really about? David Bloom, who is no relation of mine, but chairman of our department of population and international health, and a distinguished economist, has estimated on the data from Thailand that if you invest in prevention just to avert medical expenses, the returns are between 12 and 33 per cent, which as investment goes, are not bad.

If in fact you include the income losses together with medical expenditures in the broad sense in the industry and society, the returns from an investment of a dollar are 37 per cent and 55 per cent, which is really quite a return on investments that we are presently not making.

What are the characteristics of those three countries that we know about that have addressed the problem?

The first is, believe it or not, governance counts. If the president of a country says that AIDS is not caused by a virus and that one does not have to worry about sexual transmission, then no matter what NGOs do and how much money you invest, the country does not do well; whereas in those countries that have controlled AIDS there has been important leadership right from the top.

Media campaigns and informed public training of the health workers to understand how to reach out to people, targeting particularly to high risk groups that society does not like to think exist - drug abusers, sex workers - that is where it is going to come from and that is where we have to target public health. Engaging communities, particularly the poor and impoverished communities, they can do a lot to educate their people and themselves.

It is terribly important that business communities set a standard and show that industries, business can reduce the number of workers who are getting HIV and or any of these diseases, and that has a huge positive impact and sets a standard for other parts of the countries.

Partnerships with government and NGOs of course, lots of research to make real decisions based on evidence and obviously one has to put real resources in before it gets out of hand.

Let me turn now to SARS. You know it is a respiratory distress syndrome. We know that it is spread from person to person. We know it is spread, as you saw in the cough, by tiny little aerosols that are very tough to block out. We know that it is tough to diagnose. The case definition is very broad. In the United States the key test of whether someone had SARS or not was whether they had been to China. We cannot use that criteria in China, I am afraid.

So it is challenging. We know that there is a likely animal source and that is largely due to recent work from Dr Peiris at the University of Hong Kong, published in Science. It has had a very big impact in nailing down the source of this infection. But we know that the SARS virus is not always isolated from patients. That is problematic. And we also know that there is a reporting of isolation of virus from people, particularly animal handlers, who are not sick.

So the question we do not know the answer to is, is it out there in the community, or has it really gone away?

As you know, the impact in Asia has been enormous. Total world wide, about 8,000 cases; China had 5,000 cases. Total deaths of about 1,700. We know how long it takes to spread approximately and we know that the risk of death depends on how old you are. The older you are, the riskier it is that you will not make it through a bout of pneumonia with this. We do not have any idea why kids have not been prominent because kids usually fall sick to many of these respiratory infections.

There was a group of our people and a group here that asked the question -- key epidemiologic questions: how transmissible is this disease, how fast does it spread? How many people—if nobody did anything to prevent it—how many people would get infected? We can model that with mathematical models. We can also model what interventions would make a difference; what works and what would not work.

What role would super spreaders play, the small number of people. There is an example, for example, in Singapore, of the 200-and-some cases, 50 per cent, over 100, were transmitted by five people. We do not know how that works. How general is that, we do not know. Are there people who were infected and asymptomatic? Can they transmit? What is the risk of an epidemic if a single infectious case is introduced into a susceptible population.

So one starts with that last question and creates a model. This is what the key number is for a public health person, a number called "R zero" which is the reproductive number. It says, "If you have one infected person, who can transmit and bring them into a population, how many people will they give infection to that themselves will be secondary spreaders?"

The importance of that is that the mathematics has been pretty well worked out such that if that number is greater than one, in the absence of other interventions the epidemic will spread. I will show you that. If you can get that number under one, the epidemic will spontaneously die out. So it is very important to know what that number is and in fact to see what will happen.

What I have just said is the reproductive number means from one single case you get, let us say in this hypothetical model, four people infected that transmit. They each infect four, and you can see how epidemics start. Everything goes up logarithmically, not arithmetically. One infects four, four infects 16, and 16 goes up very rapidly.

"R zero" tells us a lot. It tells us the transmissibility and the duration of infectiousness, and it tells how many people will be infected but not how quickly. That depends. In the case of TB, spread is very slow. It takes a long time to get TB. For SARS it was about eight days, and that varies from bug to bug.

So it tells us about the growth rate, it tells us about the proportion of the population if you do not do the right things that have gotten infected. It gives you some idea of how intense the interventions have to be. For example, the "R zero" for measles is 15. There is no way by public health means we could stop the spread of measles. It has never happened that people could stop it. We can stop it now because we have a vaccine that prevents it, but if there is an outbreak it does its course because all the masks in the world are not adequate to block that intense an infection.

The key understanding of this disease was cracked really in multiple places, but we will take some pride. One of those places was the Harvard School of Public Health, working with colleagues in Singapore with lots of help and data from various sources, including Hong Kong and Taiwan. The other major group was a group that worked it out largely at the University of Hong Kong, with people who are present in this room and one of our alumni, Gabe Leung, we are very proud of.

The importance of this, despite the competition between the two groups, is that they came up with the same answer. That meant that in one day, in one issue of Science Magazine, the world knew how bad this infection was, and that it was not all that bad from the point of view of spread. What do I mean?

Well, in fact, the "R zero" was about three, which says that if there were no interventions and the world was pretty homogenous place, which is what airplanes are making the world, then over 100 days 70 to 80 per cent of the people of the world would have been infected with this disease. Well, the world is not a homogenous place, and lots of interventions were undertaken very quickly -- not quickly enough, but certainly quickly -- so that that is an unlikely and worst case scenario. But if it was left to its own devices, this epidemic would have spread very rapidly around the world.

What the models enable you to do is to say "what if", in my mathematical model, I introduce isolation or quarantine. What would have an effect. The model says that neither isolation would be perfect and stop the epidemic or quarantine. "Isolation" meaning taking people that are infected and putting them in an infectious disease hospital and keeping them from getting out until their infection is over. "Quarantine" means anybody who has been exposed should stay home and be locked up and away so that they do not spread and transmit whatever they are carrying to anyone else. That too is imperfect and very hard to do. The more people exposed, the harder it is ever to put people in quarantine.

Toronto balked at putting 500 people in quarantine. China had to face putting thousands of people into quarantine. So the earlier one can knock the infection, the best.

So what we learned from this, from the epidemiologic models, is: firstly, good scientists working in two parts of the world with different data ultimately should get the same answer, and thank goodness they did here. Secondly, without rigorous control methods, SARS would be a dreadful infection; thirdly, that it is low enough such that with good control of isolation and quarantine there was every reason to believe the epidemic would be stopped, and it was. We do not know if it is still out there and we are going to have to wait until the next flu season comes around to see.

But what we did learn is that once it gets out of hand, as we all now know, it is very hard to catch up, from quarantining whole towns and people.

I came in on infectious diseases. I have talked about TB and AIDS and now SARS, without mentioning the most serious epidemic facing China, which is the epidemic of tobacco deaths. China is the world's largest consumer -- 78 per cent of adult males smoke, 55 per cent of physicians smoke -- from data recently derived from surveillance in China.

By 2025, several studies indicate that about 3 million people will die of tobacco related illnesses. Of those people who are smoking now in their twenties to sixties, a third of them will die from smoking related illness. Over the next half century that is going to be about 100 million people. 100 per cent of that is preventable if you get public health right.

Let me just conclude with a couple of lessons that I think we may have learned. We know that infectious diseases can be contained when they are detected early and the number of cases is small. When they are not, they become epidemics. We know that respiratory infections are the most dangerous. We know that 20 to 40 million people lost their lives in 1918 with influenza so the bird flu threat to Hong Kong is not to be taken lightly. It is very frightening.

We know that when measles hit Hawaii, 90 per cent of the population died within a few months. And we know that there are still 8 million cases and some 2.4 million deaths due to TB spread by respiratory infection. We know that SARS causes enormous economic losses -- you know better than I. The estimates are that it was about $30 million a day in Canada. The estimates from the Asian Development Bank are about $16 billion to $30 billion in the Asian economies.

I would say they have not been devastating to the economy, and that is more, in a way, luck that the seasonal nature of the disease stopped it, as the warm weather came. But it serves as a useful warning that if you get public health systems up, you may be able to prevent the next such thing.

We learned in a way from SARS, but more importantly in the States early from the outbreak of anthrax that we are not very good in public health in the most important thing we can do which is to empower people, to give them knowledge and to communicate their risks. So the first thing we learned with anthrax, as the Secretary of Health and Human Services announced that it was a trivial problem and was going to go away, and it did not, is that you have to have a strategy of communication in advance, and almost no countries have taken the trouble to do that.

The second point I think we have learned is that you have to have a policy of full disclosure about what is and what is not known and deliver the information in a non-patronizing manner. People can handle what you know and they can handle what you do not know. They cannot handle changing your mind.

It is very important not to mix speculation, making people feel good when you do not have a basis for that and then, when it gets out of hand, you lose credibility as so many people did in the SARS epidemic and in the anthrax epidemic. I think it is very helpful to people to give a detailed accounting of what is being done to say, "We know there is a problem, the government is doing X, Y and Z. It may not be ideal, it may not be optimal, but you have to know your government is working for you."

I think you have to treat the public as an ally, not someone to be denied information, but a helper and enlist civic organizations to organize communities to protect themselves in the best way possible against something like SARS or other infectious diseases or HIV/AIDS, and give very concrete steps to ordinary people of how they can protect themselves from whatever the infectious diseases were concerned about.

I think there are some general lessons I would infer from SARS and hope you would share. The first is that infectious diseases do not respect national boundaries. The global security of people to a very large extent depends on the competence of local responses in countries around the world. The rich countries cannot protect themselves by developing good laboratories if the poor countries do not have the epidemiologists, the scientists and the laboratory people.

The second is that honest and accurate information is absolutely essential for early warning and for making effective health policy and resource allocations. In order to make an effective response, you have to have an effective health care system.

A lot of countries have been so neglectful of their public health systems that if you knew what to do and had the tools to do it, there is not a system at the local level to deliver public health as needed.

One of the things that came out in SARS that was quite extraordinary is that WHO created a global laboratory of scientists -- usually scientists compete against each other. In this case, they shared information. The University of Hong Kong was a member, charter member, if you will, of that network.

The first two hypotheses as to the cause of SARS were wrong. Had there not been a network and there were 10 other centers, or 13 centers in 10 countries, to share the information and test it critically, we would still be fighting as to whether SARS was caused by this virus or that virus or another bacteria.

By working together and getting the best available scientific knowledge counter to the scientific competitive culture was a really important thing. And creating networks should be given high priority.

Finally, investing in global health, not just SARS or AIDS, but the broadly emerging areas that have huge areas of commonality now between rich and poor countries were all vulnerable, would save millions of lives and improve the quality of life for billions of people.

I end with a commitment from our president to say that this is now a new interest of Harvard University, not just the School of Public Health, not just the School of Medicine. President Summers has described it better than I could have, which is that there are two major issues the world is going to have to address in the beginning of the next 30 years. One is the expanding knowledge of the life sciences that promises understanding of the mechanisms of disease, means to prevent and treat disease and functioning of the brain and ultimately the mind – with huge societal consequences.

The second is the increasing disparities and quality of life between rich and poor countries and within countries, and global health really is the fulcrum that links these two global agendas. I would look forward very much to trying to address any of your questions and thank you so much for your attention.

MR RONNIE CHAN: Barry, many years ago I chaired a session at the World Economic Forum in Davos in which Larry Summers was one of the speakers. We were discussing the second issue you had. I did not know that he recognizes the first as well. By the way, Larry Summers was supposed to be here during the SARS incident. Obviously he did not come. At that time Asia Society was privileged to be invited to join the Harvard Alumni Club which the president, I believe, Michelle, thanks for working with us and thanks for being here. She heads the Harvard Alumni Club here, together with HBS, the Harvard Business School Alumni Association. So we still hope to welcome him some time.

But you did mention, Barry, over lunch that you as a university, and that is between Larry, you, plus, I think, one other person, somehow decided that Harvard should take steps to prevent SARS from hitting Harvard and so before any country did it you as a university did it. What did you do and how did you come to that conclusion?

PROFESSOR BLOOM: Harvard University has 18,000 students generally packed in like sardines. A university is an epidemic waiting to happen. President Summers was deeply concerned because we have so many students studying in China, so many visitors coming up and back from China and South East Asia. He called an ad hoc group of people together, the head of the Harvard University Health Service named David Rosenthal who runs all the medical services for students and the dean of the School of Public Health. There were days we would have three phone conversations a day, sometimes three a week.

We did not want to do what Berkeley did, which is forbid people from travelling to China or forbid people from China or South East Asia from visiting Harvard. But we did not want to create an epidemic. The compromise we made was to warn people that if they came to China, they were free to come or to Asia, any of the afflicted countries, they might, upon their return, have to be put into quarantine for up to 10 days.

That had a hugely positive effect in the sense that voluntarily a lot of people who did not have to travel chose not to, and that lessened an awful lot of the problem. The second thing was then that anyone who did would have to stay in quarantine and I am pleased to say no one actually was ever put in quarantine. People did have their fevers monitored, as has been done here, and we escaped the epidemic, and I think we escaped the discriminatory activity of classifying everybody from Asia as a major threat to the United States. It was a very interesting time.

MR RONNIE CHAN: Very good. I understand that the University of Hong Kong is thinking about setting up a School of Public Health. We need you. We did not need you last year, but now we certainly do.

The floor is open. We have many experts here. We have some students here. We have a lot of medical doctors here.

QUESTION: You mentioned the anthrax scare in the United States and in fact this is not necessarily public health. But at one of the Asia Society programs on terrorist activity and the ease of terrorist activity, anthrax was used as a possible example of a terrorist weapon. So is anthrax something that we really have to continue to be concerned about?

PROFESSOR BLOOM: It would be a mistake to separate what I will call introduced infections—purposeful bio-terrorist introductions of infectious agents—from emerging infections that occur naturally. One of the problems is that if anthrax appeared in cattle in China, as it did in cattle in Russia, is that because it was in the ground and the spores came up and infected the animals spontaneously? Or is because there was a germ warfare facility, as there was in Russia, that spewed anthrax all over an area.

We have very few means to be able to distinguish between a natural infection and an introduced infection. The consequences of that are that the only way to protect ourselves is to protect ourselves by strengthening a public health system that does not care what the origin of the infection is but is on the ground prepared to set up isolation hospitals, to provide the necessary masks or whatever is required, and that would be helpful in the case of anthrax, and to provide the communication to the public of what to avoid and how to avoid it.

I would have to say that when you look at bio-terrorist agents, and I have served on the United States National Academy of Sciences; I co-chaired that committee on bio-terrorism. Anthrax is not the worst case because anthrax does not spread from people to people. So if you put anthrax in this room, we would all die, and if you locked us up no one else would die.

But the fact of the matter is there are many other things like SARS, like smallpox, that spread like measles, that spread from person to person, and the control of those will be extremely difficult.

I would guess lots of people have access to anthrax. What we most hope is that there really is nobody that has smallpox outside of the two laboratories, one in Russia and one at CDC in the US. There is a lot of skepticism that that is the case but we really do not know if that is the case.

QUESTION: Professor Bloom, thank you very much for a very interesting presentation. Regarding the "R zero" in the equation, does that not depend -- I am very ignorant about public health concepts, but does not "R zero" get affected by factors such as the viral load that a particular infected person may carry or the distance between that infected person to the susceptible individuals.

You were going to mention also the event of super spreaders. In Hong Kong now we do not call them super spreaders. We call them super spreading events, meaning that there will be cluster of factors which come into play which then contribute to the development of a super spreading event.

Could you actually put all these into equation when you talk about the "R zero" concept?

PROFESSOR BLOOM: The answer is yes. First of all, it is a very sophisticated question and I thank you for the question.

All of those things have to be taken into account and so the footnote to the paper that my junior faculty did is pages and pages of differential equations putting in all of these other factors and the fact that a city is not a complete blank space but there are buildings that interrupt the flow of air. So it really does matter how many people you see in a day, how close you are to them.

One of the peculiarities of SARS is that there is a huge variation in the ability of one known infected person to infect someone else, much higher than many other infections, which says that there are factors - possibly the amount of virus they have, possibly the amount of contact time, possibly the distance between people breathing, possibly the geometry of the room - such that two people exposed to the same person would not necessarily get the same dose. It is a very wide variance which means it is less predictable than many other infectious diseases. Good question.

QUESTION: Professor Bloom, I would like to find out how far is the industry going to be able to manufacture a vaccine. The second question is that I want to find out your personal opinion in terms of the sales of civet cats as a gourmet dish.

PROFESSOR BLOOM: My wife is a vegetarian so I have to be very careful with the latter.

Let me start with the first question because it is a really important question and very related to the bio-terrorism question. What is the market for a SARS vaccine? What is the market for an anthrax vaccine? What is the market for a smallpox vaccine?

Well, the answer is, right now it is zero. Nobody on the planet that we know of is suffering from SARS. We have no smallpox. Who would be the market? Who would pay to have the vaccine?

The vaccine business is a very curious economic phenomenon, even more peculiar than the drug business. In the vaccine business all of the investments have to be up front; the factory, the production, the reproducibility, the bottling -- all of that is investment up front and you do not know with a new vaccine whether it is going to work and be licensed by the Food and Drug Administration. So if it is not, you lose all of your investment. It is a highly risky business.

So what we know for these diseases is that there is no private market, or very little private market. What the United States Federal Government has done, which I think is a very big step and it is the first time ever, they are actually buying vaccine. So they have commissioned research on anthrax vaccine because anthrax is a very obvious target of someone who wants to kill a lot of people and make a lot of terror, but does not want an epidemic that will go around the world that no one could control. They may be that rational.

But there is nobody buying that vaccine except the Federal Government, so there is in fact a stockpile being made in the United States at enormously high cost. But there would not be vaccines other than that.

I am happy to elaborate on that, but that is the circumstance. This is a public good to protect people against a disease that does not happen. Once SARS comes back again, everybody is going to want a vaccine and it takes a year to make a vaccine, at the very earliest, if you know what to make. And we do not really know that yet for SARS.

So it is very important to think about the need for investment as a public good to protect people against diseases that are not here. That is the best thing you can do in protection.

In terms of civets, I do not have any idea what a civet is, but from talking earlier with Carrie Lam I think there is a real challenge. There are markets that are traditional and culturally important that would be very hard in many countries of the world to make disappear. There is absolutely no reason why one cannot make them sanitary. We have had a running battle in the US with the food production industry for cattle and meat where, up until 1996 or 1998, the only test allowed to be used for inspecting meat was to smell it or look at it.

Here we have all these molecular techniques that could pick up the bug and identify it. They were not allowed by law to be used. It took a huge battle over ten years by the scientific community to say that we really want to protect our food sources. There are new technologies, that is what we should be using.

I would strongly urge, if you have to have sacrifice of civets for whatever traditional reasons, it be done under the most sanitary of conditions and be inspected.

MR RONNIE CHAN: But Barry, your first question if I may be allowed, does it not argue for the government spending the money to do the research and manufacture the vaccine? As a businessman I am not going to do it.

PROFESSOR BLOOM: Yes, and when you say "the government", at least in my country "the government" is us in the sense that it is our tax money and this seems to be a very good use of tax monies rather than the $30 billion to $60 billion cost when you have an epidemic like SARS and the economy loses that money.

MR RONNIE CHAN: But is the Federal Government doing it?

PROFESSOR BLOOM: Yes.

MR RONNIE CHAN: It is, not just buying but also developing?

PROFESSOR BLOOM: No, no. All the research is supported, in bio-medical research, the major supporter of that is the Federal Government, the National Institutes of Health. What they have never done before is compete with industry for products. There is no competition here. Industry will not touch it unless they are assured of a market.

QUESTION: Professor Bloom, I enjoyed your talk and as always it is very, very - not only entertaining but very educational.

I would like to respond to a few things you said which I thought summarize most of the facts. At the start you mentioned that public health people, when nothing happens you are not around. But when something really drastic happens, you are most important. I think that is very, very true. Round the world you see that for the last 20 years or so the health care professions are all moving towards the cutting edge of medicine. They want to do genome studies, et cetera. Public health seems to be somehow ignored. But we never realize that actually infectious diseases and all that are always around the corner, old ones and new ones.

The second thing which actually troubles a lot of people in mind in Hong Kong is why did SARS, in Hong Kong in particular, drop so rapidly? I think you gave us a lot of answers there. There are basically three things. One is better contact tracing, as it were. You said to close all the doors inside and all of us will be dead but people outside will be okay. Second of course is quarantine, and again it is a point. I think the third thing is that we know more about the disease. Our health care workers know more about how to protect themselves and the patients.

But two things always trouble people's minds. One is why is it that SARS occurs more frequently -- actually the numbers are more frequent in areas in places which are more affluent: Toronto, Singapore, Hong Kong, Beijing; but not in places which are not affluent. And why did it affect health care workers proportionately more than others? I think this is still an area which is going to be interesting.

But as we move along I suppose two very points that you bring up are also very, very important. One point is that we must be prepared. The WHO alert, for example, we in Hong Kong moved through a red, yellow, green alert. I think these are basically something that we want people to learn about.

Finally, one message you brought up too on your last few slides is that health is everybody's business.

PROFESSOR BLOOM: I like that very much. Thank you for your very thoughtful comments. That is very, very good.

QUESTION: Should we really realistically be very aware of bio-terrorism?

PROFESSOR BLOOM: I cannot speak for Hong Kong certainly and I would guess the risks here are pretty minimal. I think the US has a lot of reasons to take it very, very seriously, and I think the UK and parts of Western Europe as well.

I think the world -- I am not a political scientist -- the fundamental thing that changed is that we always assumed that terrorism would occur when someone wants to kill someone else but does not want to be at risk. This is why bio-terrorism -- you know, the Germans in the Second World War, the Japanese in the Second World War, had had tested -- killed 10,000 people in Unit 731 in China with plague and other things. They did not use it because they were afraid that they would be killed.

The new dimension for me in terrorism in this recent decade is that people are quite prepared to die themselves to kill many more people. That makes it a very much more difficult challenge.

QUESTION: One last question, Barry. China is a developing country and medical science I suppose is not that advanced. It cannot be given the per capita income and so forth. How do you assess China's performance in the SARS epidemic. And in general can you make some comments on the public health system in China, where do they need to go, the education, whatever. Can you just make some general comment. I want to have some idea of how you assess.

PROFESSOR BLOOM: I could probably do better when I return from Beijing but I will not duck the question.

I think my invitation was to come and ask the question whether my school could be helpful to the Government of China in dealing with SARS. I think my real interest is asking whether my school can be helpful in analyzing and thinking about a health care system.

There are huge systemic problems and if I may answer Professor Leung's question -- just because you are rich it does not mean you have a health care system in Toronto, and that is the challenge, which is to create not just one or two people but we are really talking about a system that people trust and can go to. This requires a significant investment and communication that that investment is there, that people can see it.

The consequences are, I think, that I hope there will be renewed interest in China to invest, not just in buildings and real estate and industry, but also in the human services that keep their people's quality of life high.