Introduction & History of Public Health
Welcome to this course on global public health. Quite often we are asked what is public health? How is it different from clinical medicine? Is it something to do with water and sanitation or is it something more? And for even people who have studied a bit of public health, they say, how is it different from epidemiology, which understands the causes of disease and identifies the means to prevent it. Others wonder what is global public health? How is it different from international health or public health in general? So let us start examining some of these questions. Firstly, public health looks at the determinants of health which act at the level of populations, or people has a whole in a community or a country, and then tries to influence those determinants so that ultimately the impact is on improving the health of individuals who constitute that community or that population.
So it doesn’t deal with the individual disease in terms of trying to identify what a person’s clinical complaint is or by providing treatment that one individual as clinical medicine does. On the other hand it tries to set right some of these determinants at the societal level so that people don’t get ill. It also tries to create robust health systems which will deliver health services in a manner that is effective as well as equitable so that people can get protected against diseases through preventive services as well as get a wider range of diagnostic, curative, palliative and rehabilitative services as needed through a well-functioning health system. And all of these also have to be done cost effectively in a manner that the health system doesn’t become bankrupt and individuals have to be protected against health related impoverishment. One of the main driving values of public health is not only to improve the health of people within communities and populations, but also to insure that there is greater degree of equity. Because even in countries where the health standards are considered to be generally very good, we see several population subgroups who do not enjoy the same good health. And we find wide disparities in life expectancy, in maternal mortality or infant mortality or even cardiovascular mortality, between these groups. So public health also aims to reduce those gaps and bridge the inequities. And when we apply the standard of equity across the world, public health then becomes global health and it also starts to examine the determinants which actually act across the global level, across countries in a transnational manner and also tries to provide a concerted multinational or a concerted worldwide response so that these determinants can be further modified to improve global health.
Now if you look at clinical medicine and take the example of somebody who died of a heart attack, well the clinician, the cardiologist would say that the person died because of blockages in the blood vessels to the heart. Absolutely true. But then the epidemiologist would say, the person developed those blockages because he had consumed tobacco as a cigarette smoker from the age of 16 and therefore he had a premature heart attack at the age of 42 and died suddenly. And therefore the cause of death according to the epidemiologist is smoking tobacco. But then the social scientist would say that in virtually every country of the world, now tobacco consumption is much more among the poor. And this poor person had consumed tobacco because he fell, trapped into the habit, did not have adequate information about it. And after having developed some other cardiac problem, did not have the ability to seek affordable healthcare and therefore died of it.
Therefore the social scientists would write down the cause of death as poverty. Now every one of them is correct. And therefore public health has to look at not only the immediate cause but the combination of causes and the causes of causes. And that is where public health becomes a very broad, integrative discipline which makes the understanding of health and disease much more holistic than any single branch of medicine.
Now in terms of public health, we also have to look at systems as I said, are doctors and nurses available in adequate numbers? Are for example affordable medicines available, accessible? Let us take for example a person who meets a nurse or a doctor in a clinic.
That is clinical medicine, if the blood pressure is being checked up and some drugs are being prescribed. But what happened to the person before he came to the clinical facility? Could the problem have been prevented by appropriate advice on how to protect health to the community? Could it have been detected early, before it went into the stage of established disease or complications? Could the referral system have functioned better by providing a timely referral? All of these issues are part of public health.
When the person leaves the clinic or the healthcare facility, are the drugs that have been prescribed by the doctor, are they available in the market? Are they affordable? Can they be taken on a long-term basis? Are the kind of dietary prescriptions given in terms of fruit and vegetables? Are they affordable again in the market? Or if it’s an infectious disease, are there systems for isolation? Are there rehabilitation support systems available for a person with mental illness, or with any other form of physical disability? All of these come under public health. Even what happens in the healthcare facility is also public health because we have to find out firstly, was there a doctor, was there a nurse? Were they adequately trained? Were they following standard management guidelines?
So the whole system organization is also part of public health. So if you want even clinical medicine to function well, you need a very strong public health system. And when you take it on the global scale and look at the determinants of disease and health on the global scale, and look at systems functioning on the global scale, including the production, export, import, regulation of drugs for example, all of that is part of global public health. So public health really covers health systems, services, policies and other sectors too.
For example, when we look at what happens in terms of agriculture, food systems and the effect on nutrition, that again has to be aligned to the health of the people. Now you may say, why do we actually think that public health links to every single system, whether it’s urban design, urban transport, agriculture? Now is there no limiting factor for this? Then we have to really understand that is the primary intent of any measure is to protect health, then that is public health. Like for example, if we say, a seatbelt law, or a motorcycle helmet law, that is public health because the primary objective is toprotect health. If the primary measure is for some other objective, but still we need to align those policies and programs and those sectors to the objectives of health, then that is not strictly in the domain of public health, but public health needs to link up with it. The primary objective of agriculture may be to provide food security, may be to provide cash for the farmers, but even there we have to insure that agriculture and food systems are producing the kind of products that are better suited to human health. So that becomes an extension of public health into another sector. So public health is truly multidisciplinary in very many ways. Now when you look at how public health has evolved this is not a new concept. Even in the Roman times there was a diversion of human waste and the Roman civilization knew that if human waste accumulated, that would be a cause of disease. That was a good public health measure.
In the 19th Century Europe we saw the so-called miasma theory coming in where they felt that miasma was bad air caused by rotting organic matter and they attributed all kinds of diseases to miasma. We know that’s not entirely true, but we also know that it is important to have clean water and good sanitation and the beginnings of the sanitary movement in Europe actually brought about marked advancement in the health of the population and that was good public health. We also know that public health can use several technologies. For example, vaccination.
Vaccination again is applied at the population level so that individuals do not get the disease. Like for example, Jenner’s vaccine in 1796, Edward Jenner brought in the vaccine against small pox. Though it is said that the Chinese used this form of variola inoculation as early as a 1000 b.c., but anyway modern documented history attributes it to Jenner. In 1747, James Lind, an English sailing captain experimented and then proved that serving lime to sailors prevented scurvy, otherwise which was a major problem on long sea voyages. And that is why the English came to be known as limeys in slang.
The history of modern public health in London began with an act of vandalism. Yes. Somebody actually broke the handle of a water pump and carried it away. And this was John Snow.
In the Broad Street in London, where there was an outbreak of cholera, where cholera was spreading across in concentric circles and affecting a large number of people, John Snow mapped out how the outbreak was spreading. And then found that the center of the circle was a pump which was actually resulting in bad water coming out because of contamination with sewage. So John Snow broke the handle of the pump and the outbreak ceased. So it’s an important measure of public health to link sanitation and good water quality to people’s health. We have had several public health movements across the world, but at the level of global health, the World Health Organization which was established in 1948 became the principle catalyst and custodian of global health movements across the world, legitimized by the will of all nations.
And one of the success stories led by the World Health Organization in terms of public health has been the eradication of small pox. We know that this very deadly infectious disease have claimed a large number of lives and even in the beginning when people started getting inoculated, there were many people who did not believe in its effectiveness, but it was very clearly shown that those who were inoculated had very little mortality whereas those who were un-inoculated had a very high fatality. And the global eradication of small pox is one of the grandest success stories of public health.
But we have also seen public health evolving in terms of the understanding of the links between health and development. In the World Health Assembly of 1977, there was a resolution of health for all which resulted ultimately in the Alma-Ata declaration which also emphasized the importance of primary health services. Then it was decided that in the whole area of environmental sustainability health also needed to be accommodated and that came about in the Brundtland Commission of 1987. But the question was whether health would automatically benefit from economic development or investments in health also were needed for accelerated economic development. And that conversation began in terms of this bidirectional relationship in the World Development Report of 1993, investing in health. It was advanced then by the Commission of Microeconomics and Health which was formed by the World Health Organization. And recognizing that health and development are integrally related, at least three direct health related goals were accommodated in the Millennium Development Goals of 2000 which were adopted by the United Nations.
And now as we move towards 2015, when the United Nations is looking at adoption of sustainable development goals, the whole relationship of public health and global public health in to sustainable development is so abundantly clear that we see global health as one of the important points around which the SDG’s will revolve. We will find they’re in one way or the other linked to global public health objectives.