Health challenges for research in the 21st century
David E. Barmes Global Health Lecture
David Barmes worked for WHO from 1967 to 1992, and is remembered as a highly capable Chief of the Oral Health Programme, an excellent scientist, and an effective global strategist for health. It is people like him who give WHO its strength and makes it work. I am happy to be continuing his work by contributing a lecture to this series.
My aim in this presentation is to put some of our present concerns about global public health into their historical context, so that we can think as clearly as possible about our present and future responsibilities.
It was already clear, to at least one person, 24 centuries ago that scientific enquiry could improve human health. Hippocrates, around 400 BC, not only introduced the method of diagnosis based on systematic observation but recommended carefully tested diets and physical activities as the first line of treatment.
It took a long time for this enlightened approach to take hold, however, and I will argue that it still has not done so as much as we need it to. In fact progress in applying scientific intelligence to health did not really start to pick up speed until about 21 centuries after Hippocrates had started it.
There have been three kinds of breakthrough we can use as reference points for our current concerns: a cure, a prevention method, and a vaccine. They are discoveries associated with individuals, but they also reflect the efforts and talents of many people, both before and after the event. I will use one example from each of the three centuries preceding this one:
- James Lind's publication of a cure for scurvy in 1753;
- John Snow's demonstration of a way to stop cholera in 1854;
- and Jonas Salk's discovery of a vaccine for polio in 1954.
I will end by mentioning some current research needs. My main point is that research has already been giving us the means to control and prevent most of the major disease threats of today. The challenge before us now is also to make good use of them.
A cure for scurvy in 1753
In the 18th century, scurvy was killing thousands of people every year. More sailors in the British Royal Navy were dying of it than from enemy action. James Lind published his Treatise of the scurvy in 1753. It has been called one of the earliest accounts of a prospective clinical trial, comparing six commonly used treatments of scurvy. It also includes a systematic review of what had previously been published on the diagnosis, prevention and treatment of scurvy.
While serving as a naval surgeon in the Channel Fleet in 1747, Lind selected 12 sailors who were all at a similar stage of scurvy, had the same basic diet and were accommodated in the same part of the ship. To two each he allocated one of six of the many different treatments for scurvy then in use:
- a quart of cider a day;
- 25 drops of elixir vitriol three times a day;
- two spoonfuls of vinegar three times a day;
- half a pint of sea water a day;
- a concoction of nutmeg, mustard and garlic three times a day;
- and two oranges and a lemon a day.
Lind reported: "The most sudden and visible good effects were perceived from the use of oranges and lemons; one of those who had taken them being at the end of six days fit for duty… The other was the best recovered of any in his condition; and being now deemed pretty well, was appointed nurse to the rest of the sick."
Lind left the Navy after that voyage and returned to Edinburgh University, where he reviewed the literature on scurvy. He identified 54 books on it worthy of critical appraisal, and wrote an abstract of each of them. The evidence that fresh fruit and vegetables both prevented and cured scurvy was overwhelming.
During the following years, Lind's 450-page treatise was published and republished, in English, French, Italian and German. Enlightened individuals like Captain Cook were strict about taking in fresh fruit and vegetables at every opportunity and making sure that every man on board ate them. As a result, the mortality rate for his voyages was outstandingly low. But it was only a year after Lind's death, in 1794, that the Admiralty provided lemon juice for its sailors on a large scale. The effect was dramatic. Within two years, scurvy more or less disappeared from the Navy.
The necessary information and knowledge was there for all to see, but it took the British naval authorities 40 years to get around to applying it.
In our own time we see the same delays, or arguably worse. Richard Doll and Bradford Hill published their landmark study showing the link between smoking and lung cancer in 1950. It was neither the first nor the last such study, but is seen as the one which 'launched the case against tobacco as a leading cause of disease'. Concerted international action on a large scale to curb tobacco use in Europe and the United States did not take place until decades afterwards. Globally, we still have a very long way to go to apply non-smoking as a simple measure to prevent 5 million deaths a year. This number is expected to grow to 10 million by 2020.
The WHO Framework Convention on Tobacco Control will enter into force on 28 February 2005. Last week the 40th country, Peru, became state party to it. This means that it will become binding as law for all its parties. It is a great achievement and we are celebrating. But even with this support, there is an urgent need for decisive action by governments, and by the public, if tobacco-related diseases are to be reduced.
The WHO Global Strategy for Diet and Physical Activity was adopted last May by the World Health Assembly. It recommends measures that are easy to follow and provides inescapable evidence for their efficacy. Such measures can save large numbers of lives of men and women in the prime of life and at the height of their abilities. They can also save health services and national economies large amounts of money.
Where the ingenuity and systematic approach of Lind are urgently needed now is in finding ways to ensure that the knowledge of nutritionists and noncommunicable disease researchers is fully synthesized, understood, and applied.
Stopping cholera in 1854
Asian cholera entered England in 1831, through the seaport of Sunderland. John Snow was an apprentice physician at that time, and assigned to help patients in the Newcastle area. He quickly discovered that existing medicines were powerless against this disease, which killed within hours of onset. By studying that outbreak and subsequent ones in London, he became convinced that the transmission of cholera was faecal–oral and spread mainly by contaminated drinking-water.
In the outbreak in London in 1854, as we all know, he set out to prove this theory by studying the death registers, making door-to-door enquiries to track down chains of transmission, and analysing London’s water supply and sewage system. Snow marked each death on a street map, together with the location of each public water pump. Within 10 days there had been 500 deaths in one small area, 50 of them within 50 feet of the Broad Street pump. He also found out that most of the people who had died in the neighbourhood drank water from that pump. Households that used other pumps suffered no casualties.
Snow noted that a sewer line ran within a few feet of the pump. In addition, microscopy was sufficiently advanced at that time to show that the water from that pump contained a good deal of organic matter.
Snow took his findings to the Board of Guardians of St James’s Parish on September 7, 1854. They took his advice and removed the handle of the Broad Street pump. As Snow had predicted, within a few days the outbreak began to subside.
It could be that the epidemic had peaked out anyway. But the main point is that 29 years before Koch’s microbiology identified the vibrio cholerae, Snow’s epidemiology had produced a powerful body of evidence for preventive action. The parliamentary committee to which he later presented his findings was not convinced by them initially, however, and stuck to the traditional view that cholera was an airborne disease caused by miasmas. It took several more years and thousands more deaths for enough evidence and political pressure to accumulate before the decision was taken to construct a proper sewage and drinking-water system for London.
One moral of this story is that public health can save more lives than individual medical interventions. Cholera was a frightening mystery in an individual patient, but a great deal could be done to stop its transmission. It just needed someone brave enough and persistent enough to gather the evidence.
The same was true of SARS last year. It was stopped by the same basic methods of epidemiology that John Snow used: mapping cases, investigating transmission, analysing findings, drawing conclusions and taking action. In 2003 that was made possible by rapid information exchange on a worldwide scale and the willingness of scientists like yourselves around the world to pool their knowledge and skills.
A second moral of the Broad Street pump story is that local authorities can often act much more swiftly and appropriately than larger government bodies. Where people are well enough informed they do not have to wait for large-scale action. Disabling a pump does not require a degree in rocket science, or a national or international consensus, or meetings. Knowing that it was necessary did require excellent and sophisticated research, and that had been done. The next step, of making that knowledge available where it was urgently needed, is equally important. That is why in WHO we do everything we can to support local action based on reliable information.
But self-help still needs a functional society in which to operate, so our mandate is to work with governments to build national and international health systems. This dimension of health work is often seen as beginning in 1851 with the first International Sanitary Conference. It met in Paris to agree on shipping and docking regulations for disease control. The main objective was to stop the spread of cholera, which was killing people by the thousand across Europe and causing massive financial losses.
Last month, just 153 years later, representatives of our Member States met for two weeks in Geneva to agree on the next revisions to those regulations. The last major rewrite was in 1969, when the world was quite a lot different from what it is now (for instance, smallpox was still a concern, and AIDS was not yet known). For the current revisions the centre of attention is the danger of an influenza pandemic. The revised regulations will be considered by the World Health Assembly in May next year. The world’s health depends increasingly on such agreements and arrangements, but it equally depends on individual and local initiative. We do not have to wait for the perfect solution. In many cases we cannot afford to.
A third moral I would like to mention from the story about John Snow is that the determinants of health are social as well as biological. It was mainly the poor who were devastated by the cholera epidemics. Disease and the effort to control it revealed the need to build a safer and more just society. That meant adequate water, sanitation and living conditions for everyone, as well as reliable health care systems. Otherwise everyone was at risk.
Exactly the same is true for the diseases of poverty today. To speed up the process of making this clear and acting accordingly, we are launching a Commission on the Social Determinants of Health in March next year. It will be examining some of the social disadvantages that cause health problems, and what to do about them. The health sciences have found ways to prevent or control most of the diseases that are killing children and younger adults today, but they are powerless without the necessary social support. History shows that support comes when there is a clear enough understanding of how living and working conditions affect people's health.
We need people with the courage and persistence of John Snow to gather the evidence, interpret the findings, and make them clear to policy-makers.
A vaccine for polio in 1954
I've brought Jonas Salk into this because he too started something that is still waiting for us to finish.
Salk embarked on systematic research for a polio vaccine in 1947, when he was 33, working at the University of Pittsburgh Medical School and with the National Foundation for Infantile Paralysis. He discovered and developed inactivated polio vaccine in 1952. Two years later 1.7 million children in this country participated in the field trials for this new product.
Many western countries, as well as the US, had been trying to fight epidemics of this disease, which killed or crippled people for life. In spite of precautions such as closing swimming pools and movie houses in the summer, children and adults in their thousands were paralysed, either lying in iron lung machines or struggling to walk with crutches and in leg braces. Polio was a major source of grief, anxiety and panic in those days.
The news of Salk's achievement caused an international sensation. He added to his own glory with his famous answer to the question of patenting. When asked who owned the new vaccine, he said, as I am sure you all remember: "The people! Could you patent the sun?" Opinions differ about Jonas Salk, but that was indeed a famous answer.
Of course, his discovery was soon followed by that of Albert Sabin, of oral polio vaccine. With these highly effective and affordable products, hundreds of millions of children were protected. Polio was gradually recognized as an unnecessary affliction, and in 1988 the World Health Assembly launched the Global Polio Eradication Initiative.
Poliovirus transmission is still occurring in Afghanistan, Egypt, India, and Pakistan, where it can be stopped by the middle of next year, and in Africa where it can be stopped by the end of next year. The end is in sight, but we still need a very high degree of mobilization and persistence to complete this task.
Salk showed how with a strong social movement, faith in science, and generosity, it was possible to solve one of the toughest and most dangerous public health problems of his time. We still need that spirit to finish his work.
That is also the kind of strength we need very urgently to tackle HIV/AIDS. Treatment for this disease has existed since the 1990s, but six million of the people who need it are not getting it, and are consequently dying. They are dying not because there are no effective drugs but because they are too poor to obtain them, and there are no health systems to provide them.
Last year WHO and UNAIDS launched the initiative to get 3 million of those people onto treatment by the end of 2005. We see this as a first step to universal access and an indispensable support for activities to prevent HIV transmission. It is an emergency initiative. AIDS is destroying whole societies in some parts of the world.
Treatment requires not only affordable drugs but functioning health systems. Last month I attended the Ministerial Summit on Health Research, in Mexico. The aim of the summit was to direct research efforts at tackling the diseases of poverty. The participants found that there already is a wealth of innovation at country level, waiting to be used and built on. They also found that many of the challenges to health systems are the same in poor countries as they are in rich ones. Some of the most pressing needs are for quality, safety, equity and fairness.
There was a large amount of agreement on the areas of research that are most needed now. They include diagnostics, drugs, vaccines for the priority diseases, of course. But equally important if not more so now, they include the social and environmental requirements for good health. Most importantly of all, these factors need to be understood as part of a coherent system and set of approaches.
That is why at the centre of most people’s concern was the need for research on health systems that will meet the needs of our own century — the 21st. These systems will not just evolve of their own accord. They have to be designed and built, with just as much expertise as an urban water-supply system. Effective and reliable international and national health systems are urgently needed now.
The people who run them have to be well-informed, and make full use of the available technologies. They also have to take fully into account the social and economic factors involved, as well as the medical ones.
The three researchers I have talked about were unusual individuals but they were also part of social movements that were characteristic of their times. Lind was a man of the Enlightenment; Snow was part of a rising tide of alarm at the inhuman living and working conditions that had come with the industrial revolution; Salk was supported by the March of Dimes and a great popular movement of solidarity in the USA for the victims of polio.
As individuals they gave strength to those social trends, just as they drew strength from them. They were living in difficult and dangerous times, just as we are. Like them, we need to work with the positive trends in our own time.
They were great scientists, each in quite different ways, but they also had admirable human qualities, and those are an important part of the secret of their success. They were courageous, persistent and generous. Wherever people are thinking and working with that kind of intelligence, the necessary discoveries can be made.
David Barmes was an excellent example of this approach. He represents many others who usually remain unrecognized. I would like to use this opportunity to remind us of the importance of working in this spirit. With the combined expertise and roles of our organizations we can meet today's health challenges, and continue the work of our great predecessors.