Trends in Public Health III

Globalisation and its Impact on Public Health

We now live in an increasingly interconnected and interdependent world. If industrialization and urbanization constituted the principle propellants of economic growth as well as health transition in the 19th and 20th Centuries, globalization constituted the tailwind that accelerated health transition towards the end of the 20th Century. This we have seen in the way non-communicable diseases have now become a global phenomenon. We have also seen how knowledge as well as technologies have been used to better control infectious diseases across the world. So globalization offers us advantages as well as disadvantages.

So naturally we find enthusiastic supporters as well as very strong skeptics. We need to critically look at how the advantages of globalization can be amplified while curtailing some of the absolute disadvantages that it has brought to global health.

Globalization has been defined as a process of greater integration within the world economy, through movements of goods and services, capital, technology, labor, all of which lead increasingly to economic decisions being influenced by global conditions. We see that the world economy now is increasingly being dominated by the forces of globalization, whether it is the spread of infectious diseases through rapid movement of people, or even the global contagion of economic crisis which affected the banking system in the first decade of the 21st Century. In such an environment you can have the forces of growth fueling production and employment in other parts of the world, but you can also have an increasing vulnerability where financial systems are actually either unstable or inequitable. Globalization affects health in several pathways.

Firstly, in terms of a direct impact on health systems as well as a direct impact on health policies. There is also an increasing exposure to hazards like infections, tobacco and other marketed products. But it also affects indirectly through the impact on national economies. For example, health sector affects the public health expenditure on health in terms of globalization influencing some of the policies related to allocation of resources, both through the health sector overall as well as within health itself, resetting of priorities for expenditure. We also recognize that there can be increasing effects on population risks. For example, on the kind of diets that people now start eating as a result of the global marketing forces and that has an impact on nutrition. And in turn, on health. Living conditions are also substantially altered by the forces of globalization. And all of this cumulatively can decide on whether the impact of globalization on health is positive or negative. For example, we see in the case of Central America the import of snacks from the United States has markedly increased as a result of trade between 1989 and 2006. And we see overweight and obesity rapidly rising in that region of the world, especially in Mexico. And also in other Central American countries. We recognize that we can also have the market liberalization bringing in healthy foods. Like in the case of Poland, where the opening up of the markets brought in much more vegetable oils which were healthier than the animal fats that were being traditionally consumed. And also a greater amount of fruit and vegetables.

And that resulted in a fairly rapid decline of cardiovascular mortality in the mid-1990s in Poland. So globalization in terms of nutrition can be a double-edged sword, depending upon which type of products are being marketed and are being consumed. At the same time we also recognize that trade impacts access to medicines. While this is going to be elaborated much more in a future lecture, we must recognize that lifesaving medicines can now be exported or imported worldwide. But there are barriers which sometimes prevent access to medicines because trade often prioritizes intellectual property over the social contract of making medicines available to everybody who needs them. And therefore trade is a very important area for us to look at when we see the impact of globalization on health, particularly through access to medicines. The whole area of trade liberalization was also accompanied by prescriptions for structural adjustments in the economy. And that had an impact on the way public funds were being utilized for health. During a transition to a market economy in the early 1990s, in Russia, there was a drastic fall in life expectancy, especially of the Russian males, which hit a point which was lower, lowest in a century. About 1.4 to 1.6 million premature deaths occurred during 1990 to 1995. A great proportion of these were among working age men. And there were several factors that were cited as being responsible for this effect.

Firstly the import of a large number of unhealthy foods into the Russian market exacerbated some of the poor diets that they were already having. But one of the most important factors was the deregulation of alcohol consumption which hugely increased alcohol consumption and binge drinking became a norm. And that resulted not only in increased cardiovascular disease, especially sudden cardiac death, but also a huge surge in accidents and injuries. This was also accompanied by reduced public spending on healthcare. And even some of the infectious diseases that were previously very well controlled now started springing up again.

So we saw the destabilization of the Russian health system during this period of economic transition. Again, marketization of health systems became an important feature of the prescription provided by multilateral institutions like the World Bank and the International Monetary Fund, during the late ’80s and early ’90s. And these traditionally worsened public spending on health by reinforcing the market driven approach to healthcare provision. And we are seeing how their emphasis on user fee became counter-productive. Evidence from Kenya, Burkina Faso, Papua New Guinea, all of them showed a clear decline in the utilization of health services with the introduction of user fee. One of the most dramatic impacts was seen in China, where despite the huge advantage that China had derived earlier from wise investments in nutrition, in public health, for water and sanitation, and in general, spending on provisional basic health services to the Chinese people, the introduction of market reforms saw considerable disinvestment of public finance in the health system. The percentage of women with insurance coverage for prenatal delivery, uh, prenatal and delivery services fell from 58.3% in 1989 to 34.7% in 1997. And the overall access to insurance coverage already available to just one in four Chinese in 1989 continued to decline slowly through the 1990s. This led China to review and revise its policy and introduce substantial reforms with infusion of public finance and an increase in the coverage of the insurance system through three programs to more than 95% of the population The fact that market prescriptions may have been unwise has also been acknowledged by the president of the World Bank, Jim Yong Kim, who referred to some of the prescriptions that the World Bank had made to Thailand against some of the reforms that Thailand wanted to undertake in order to launch universal health coverage. He said, “let me acknowledge that Thailand launched its universal coverage program against concerns over fiscal sustainability initially raised by my own institution. Thailand’s health leaders were determined to act boldly and provide access for their whole population. Today the world learns from Thailand’s example.” This confession that the World Bank prescription of the ’90s was incorrect came when Jim Kim addressed the World Health assembly in 2013. But the fact remains that many countries did follow the World Bank in name of prescriptions in the ’90s and that may have affected the way health equity grew among those countries. The World Bank has now formally changed its goal to fighting no longer just for the eradication of poverty, but also for shared prosperity, recognizing that mere growth itself is not a guarantor of good health, but you ought to reduce income disparities within countries if you want to gain from growth to the maximum extent. So that again is an important revision of the overall economic philosophy of the World Bank. And that may influence how globalization is perceived in the future.

When we come to the other impacts of globalization and health, we must also consider brain drain of health professionals. More than 20% of physicians working in Australia, Canada and the United States of America come from other countries. WHO estimates that there is a global shortage of about 4.3 million physicians, midwives, nurses and support workers worldwide, and the export of health workers to other countries from countries most in need of them for their own under-resourced health systems adversely affects global health. And this is a problem that we must address. And the WHO has provided a code on human migration of health workers which can offset some of these problems. But we must recognize again, that if there is a global shortage of health workers, we need a global response which provides those resources to all countries, but does not divert them from the less developed countries to the more developed countries. We also must recognize that global funding is now sometimes skewing the priorities both for health research and health programs within countries. While the infusion of a lot of private funding from philanthropic foundations and from the private sector is indeed welcome in terms of raising the overall pie of funds that is available for the health sector, if priorities are principally going to be decided by what the donors choose, then you may actually land up with priorities which are misaligned to the needs of countries as well as that of global health. So we need to build in a greater accountability into the whole system of global funding from nongovernmental sources and say that these are the kind of priorities that have to be determined by countries and by consensus among countries, and any private funding should not distort those priorities. At the same time we see the increased global movement of humans and goods can increase the risk of infectious disease spread. We have seen that for Ebola. We have seen that for SARS. So we need to be very careful about how we actually ensure the movement of people and goods during a period…during an era of accelerated globalization does not cause more of infectious disease spread, resulting in pandemics.

Globalization has also been recognized as one of the drivers of change in ecosystems. For example, agricultural production itself is greatly skewed to meet international demand created by market pressures rather than by addressing local needs. And not even in terms of looking at global health goals or national health goals, but purely looking at the commercial profit line of the crop production that has often resulted in reduced crop diversity with a much greater emphasis on some of the cash crops than  even on staples or protein sources or providing the kind of diversity that’s required for healthy diets. For example we see tobacco, meat, soya and palm oil dominating the agricultural system which are not always to the advantage of good health. Global meat production for example is now going up substantially and is likely to rise from about 310 millions of tons in 2013 to about 518 millions of tons in 2050. While we do require protein sources, this level of meat consumption is not good for health and certainly not good for the environment because of the high level of methane emissions as well as the huge amount of deforestation that is required to produce the grain that goes into feed the animals.

So we must recognize that agricultural systems which are being driven by forces of global commercial compulsions are now sometimes acting to the detriment of good health as well as the environment. And the environmental degradation in turn affects health. We also recognize that shifting of production to low and middle income countries with poor environmental and safety regulations negatively affects the environment in some ways because of increased air pollution levels, because of a number of factories which belch out a lot of carbon dioxide and other greenhouse gases, or contamination of water bodies because of poor environmental regulation. Drainage of water because of soft drink companies draining away a lot of needed water for production of their beverages in the low and middle income countries.

Or even poor living conditions whether it is the garment factory workers in Bangladesh who suffer because of fires breaking out in very poorly regulated conditions of work, or when you’re looking at people working in South African vineyards or people working the tobacco factories of India, we find that while the production forces are now investing much more in low and middle income countries,they’re not ensuring the health and safety of the low paid employees. And this is again, a distortion of globalization that we ought to correct. It has been said that globalization itself is a wonderful opportunity for equalization of opportunity across the world. And by spurring on economic growth, it’ll not only foster better health but also reduce health inequities. Angus Deaton differs and points out that economic growth by itself will not be enough to improve population health, at least in any acceptable time. Clearly we need growth, but we also need inclusive growth in which health inequities which accompany economic inequities are reduced. And Angus Deaton says that as far as health is concerned the market by itself is not a substitute for collective action. So the imperative of globalization is collective action, not just abandoning everything to the forces of the market. Therefore, we need to recognize that market interventions are required for protecting health. Even in the national context, we have recognized that asymmetry of information and decision-making power doesn’t make health a perfect market. In fact, it’s a very imperfect market. And the same thing applies even at the global level when trade and other market compulsions often negate the need for policies which are conducive to good health at the global level. Therefore, recognizing that the market is here with us and is something that we have to reckon with, we need to mold the market by adopting a number of other forces which are favorable to public health.

Firstly, we must raise consumer consciousness so that the demand for healthier products steers the industry towards them. We must also offer the industry incentives for producing healthier products by pointing out the health dividend that comes from a health society which is much more productive, which stable labor and consumer markets for a variety of goods. We need to see that public-private partnerships are much more responsible and are responsive to health concerns and produce healthier products for the global market.

At the same time, we ought to adopt national policy frameworks with political, economic, and social motivators that reduce some of the distortions brought about by globalization, whether it is nutrition which has to have incentives for healthy foods in form of subsidies, or disincentives for unhealthy foods in terms of increased import tariffs. We also need global agreements for example by way of the framework convention on tobacco control or agreements to ban advertising of junk foods and soft drinks to children. So there are a large number of global agreements also which can bring about some degree of balance in the market forces that dictate global health. As Nancy Birdsall, the director of the Center for Global Development remarked, globalization as we know today is fundamentally asymmetric. In its benefits and its risks, it works less well for the currently poor countries and for poor households within developing countries. In a very famous phrase, Thomas Friedman described the world as being flat; basically pointing out globalization has brought in a number of opportunities across the world reducing the asymmetries that existed prior to that. But even what appears to be superficially a very flat surface sometimes can be very tilted. And that is the asymmetry of power, even in a globalized world. With multilateral institutions like the World Bank, the IMF, the World Trade Organization, the distribution of power is unequal. The G-8 nations account for nearly half of the global economy and trade. They hold four of the five U.N. Permanent Security Council seats and have a major shareholder control over the International Monetary Fund and the World Bank. So even in the era of globalization, which offers considerable opportunity for other countries in the world to benefit from an integrated global economy, it is this asymmetry of both economic and political power that brings in distortions. So we need to insure that those are corrected if we are really pursuing the goals of global health and health equity. So for globalization and health what needs to be done is to make more resources available for health systems by expanding and improving the overseas development assistance, improving debt relief. That’s very critical because countries which are actually in the poverty trap because of huge, unaffordable debt need to be provided support so that they can escape the poverty trap and invest much more in their own health systems. We need to reform the international trade regime, bringing in health front and center as a consideration. And ensure that the WTO regulations do not undermine what the WHO is trying to do or what countries are trying to do. We need to consider health as a human right because unless we do that, we’ll not be able to set right some other distortions that have occurred because of globalization. We need to protect national governments policy space for addressing the social determinants of health in light of the unpredictable nature of financial capital. We can’t leave everything to globalization which brings in investment because we know how fickle financial capital is. At the earliest sign of risk, capital flees, leaving the countries high and dry. And that can have a detrimental effect on their own investments in the health sector as well as in the social determinants of health. So we ought to be able to insulate some of the fundamental things like water, sanitation, nutrition, environment and basic health services against some of the imbalances that occur because of the imperfections in the financial markets. But having looked at some of the flip side of globalization, we must also recognize that globalization has several advantages to offer. Firstly, there is globalization of knowledge. Globalization of knowledge in terms of science, in terms of technologies, all of these can be highly beneficial to humanity if they’re shared. And we recognize whether it is the causation of disease or interventions to prevent disease or reduce the impact of disease, this knowledge has been transformational over the 20th Century, can be even more so in the 21st Century. So we need to build bridges by which knowledge can rapidly diffuse across the world and act in favor of good health.

At the same time, in terms of reverse innovation, there is a lot happening in the low and middle income countries where because of some of the challenges faced by the health systems they’re coming up with absolutely brilliant innovations which are problem-solving and low cost. And some of these innovations can now become portable even to the high income countries and they can benefit from some of this new knowledge that’s being created. In terms of global financing of health, we now recognize that there can be increased funds flowing into the health sector to a variety of poor resources. Countries need not be all the time essentially living on uncertain charity. Pre-committed funds as the part of global programs for health are going to be very important for supporting some of the health system innovations in low and middle income countries and helping them to overcome their own health inequities. In terms of globalization of health norms we now recognize that communications have now transported role models across the world through the media which is now globally shared. Whereas people were looking at unhealthy foods as one of the norms, now they’re looking at healthier foods, physically active living habits as the desirable social norms. Nothing illustrates this more than tobacco-free public spaces. Now in many parts of the world to smoke in public is not only legally taboo, but socially frowned upon. And these are changes in health norms that have actually come from some of the developed countries and are now rapidly moving for adoption in the low and middle income countries.

So globalization of health norms can be very effective too. And again, this can be  didirectional because some of the traditional cultural norms and traditional health norms of the low and middle income countries can also be adopted by the high income countries. Globally shared goals are important. We’ve seen the tremendous impact of the millennium development goals and that has been an important area of global cooperation, where a shared vision enabled different countries to work together to reduce maternal mortality, child mortality, under-nutrition and poverty. But for all of this to happen, we need globalization  of solidarity. You cannot have narrow, self-serving sectoral interests driving the forces of globalization.

You need a common commitment to global good as the unifying force of globalization where we are looking at economic inequities being reduced, we are looking at health inequities being reduced and we recognize human welfare as something that we’re all concerned about as a common human family. So if we can actually make that as the unifying platform of globalization, then we will be able to eliminate or substantially minimize the distortions of globalization on global health and really build upon that solidarity for advancing global health to levels that we have never seen before and reducing health inequities to the lowest possible. Go back to start of transcript.

Trends in Public Health II

Economics to Equity in Health

We have emphasized that equity is absolutely pivotal to public health and global health. We’ve also recognized that economics are also very critical for development of countries and therefore for health.

300px-Stage5.svgWe now need to look at how economics is related to health and how it reflects on health equity. But what is equity and why are we so much bothered about it? In 2000, when the Millennium Development Goals were framed, they set as targets aggregate national health indicators,whether it is maternal mortality, or infant mortality, or poverty reduction, or reduction in under-nutrition. However, we recognize that even as countries show improvement in national aggregate indicators, there could continue to be serious gaps in equity across different social groups within the countries.

The richer sections could actually have much better declines and greater improvements in the health status in terms of the various indicators. But the poorer sections could continue to lag behind and the gaps could grow. And that may not always be reflected very well in the national aggregate indicators. So one also has to look at how these gaps can be bridged within countries, even as we move towards a greater national progress in terms of achievement of the MDG goals. The WHO commission on social determinants of health emphasized this aspect by saying that we must put health equity as central to improvement in the health outcomes. We need to look at what health equity actually means. It has been defined as the absence of disparities in health and its key social determinants that are systemically associated with social advantage or disadvantage. So these health disparities when they exist, they contribute to health inequity and reflect health inequity. But they’re not merely differences in health indicators, but also in their social determinants. We have seen economic development as a very key lever for improved health in societies. Societies tend to improve upon their life expectancy for the populations as the per capita income of the countries grows. The millennium Preston curve demonstrates that by the time countries reach a per capita GDP, somewhere between $3000 and $5000 per head, the life expectancy actually has reached a very high level and starts, plateauing off. But before that, there is a very sharp rise in life expectancy as the per capita GDP grows.However it’s not merely what is happening to the national average in terms of the income. How that income is distributed within countries also matters. At the same level of national GDP or per capita GDP, you could actually have considerable differences between different social classes.

And countries which have a wide gap in the per capita income between the upper income quintile and the lowest income quintile, tend to have poorer health outcomes in comparison to the countries which have the same level of per capita GDP, but have a narrower income gap between the upper and the lower social classes. And this has been seen very clearly in a number of countries. And one of the stark examples taken from Kate Pickett and Richard Wilkinson’s book, The Spirit Level, shows how Japan and USA, for a variety of health indicators are poles apart because Japan tends to have the narrowest gap between the income at the highest level and the income at the lowest level. Whereas the USA has seen huge income disparities among, for example its bankers and some of the workers employed in low level employment. Similarly, life expectancy also is longer in the rich countries which are more equal. If you take all the high income countries and look at which have done best in terms of life expectancy, again, Japan scores very well and others also tend to show a gradient based upon what the gaps are between the high income and the low income groups in terms of the actual income levels. So as income inequality grows, the benefits of life expectancy that you expect with an overall rise in national income tend to be diminished. Even when you look at something like obesity, this particular income gap seems to have an effect. Japan again, shows very low levels of overweight and obesity, whereas the United States of America shows much higher levels of overweight and obesity. True, you have other factors influencing overweight and obesity such as the nature of traditional diets and so on, but the fact that unequal societies tend to have worse health indicators is reinforced, whichever health indicator you take and obesity and overweight is also one more example. Mental illness again is much more highly prevalent in more unequal rich countries as compared to the more equal rich countries. And this again is a salutary lesson to show that social stability, social conflict which reflect ultimately on individual mental health are also substantially determined by the income gaps within countries.

The world development report of 1993 as well as the WHO commission on macroeconomics of health in 2001 demonstrated that good health is not only a product of development, but is indispensable to development. Many economists before that believed that health would inevitably and passively respond to accelerated economic growth. But later on it became very evident that you have to invest in health of societies and populations in order to accelerate the economic growth and to insure that avoidable illness and avertable premature death do not take a toll of economic growth. We are looking at this very clear bidirectional relationship between health and economic development where health also needs to sustain and nurture economic growth, while benefiting from the products of economic growth. So good health for all and sustainable development of societies can only be addressed by reducing inequities while promoting the overall growth. And this also has an evolution in our philosophical thought of how we understand equality, equity in society. The utilitarian philosophy of Jeremy Bentham basically said whatever is good for society is what we must invest in.

But if you look at it narrowly from a utilitarian point of view, investing in the health of children or investing in the health of elderly and disabled would not be seen as the right thing to do. So we have to go beyond the merely utilitarian point of view. And John Rawls brought that into the philosophical construct of fairness which he equated with justice. And he said, whatever is fair should be equal in terms of treatment of people in society. And that equality was equated with the equality of opportunity, of fairness across different people and different sections of people. But then Sen advanced it to a further level in terms of the idea of justice being not merely in terms of fairness but of insuring that all sections had the ability to exercise their capability for development, to be healthy and to be productive.

And herein we bring in a rather interesting concept of defining equity, either as vertical equity or as horizontal equity. When we look at horizontal equity, which is what probably John Rawls meant by his concept of fairness, we are really looking at everybody being treated equally in a society, including access to health services. Universal health coverage for example. But when you look at vertical equity, you’re also making a deliberate attempt to bridge the existing gaps by affirmative action. And therefore you are sometimes looking at targeting special programs for the poor who have been left behind. Now we do need to integrate both of these concepts, ultimately into the idea of justice even as we try and provide equality across the society, we also need to insure that some of the disadvantages that preexisted and resulted in poor health indicators for some of the population groups must also be bridged by special targeted programs and blending these is ultimately going to be beneficial for all of society by reducing the disparities.

Ultimately when we are looking at this whole idea of capability we also translate it into a right. The right to health. And that is the underlying philosophy that is now driving global health towards universal health coverage and towards a movement for greater health equity. Sridhar Venkatapuram in his book Health Justice, defines this very well. He says, a well ordered society would insure that all individual, all individuals have the capability to be healthy and at a level that is commensurate with human dignity in the modern world, which is their right. So the right to human dignity, the right to development is something that is recognized, but that is dependent on a capability to be healthy. And it is that capability that must be fostered by economic development and equitable distribution of the products of economic development. And then only we can see health equity.

R.H. Tawney who was a clergyman economist in the early 20th Century in England remarked upon this, saying- what is required is not only an open road, but an equal start. When we talk of equal opportunity we forget that we’ve actually created sufficient disadvantages for some people who cannot make the same use of the opportunity as the person who has had previous advantages. So you can’t expect them to run the race at the same speed. So Tawney remarked that with massive health inequalities where many are denied an adequate education, unable to access effective healthcare and housed in slums, equality of opportunity is nothing more than a cruel jest. The impertinent courtesy of an invitation offered to unwelcome guests in the certainty that circumstances will prevent them from accepting it. He called it nothing more than decorous drapery. So that is where we bring in the social determinants of health. Not merely by offering equality of opportunity through a universal health coverage to accessible health services, which is essential, but also to ensure that we address the social determinants of health which define the conditions under which individuals can get an equal start and run the race without handicap. So when we’re really talking about social determinants of health and capability for individuals, we are also talking about extending that capability beyond individuals. We need equity among communities within a country. We need greater equity in health indicators as well as economic development among countries. And importantly in the 21st Century we also have to think of intergenerational equity. We cannot use all the resources that are currently available or most of the resources that we have to our advantage and deprive the future generations of those resources. We cannot create conditions in which the environment is going to be so degraded that the future generations cannot lead a healthy life. And that is why the concept of equity is no longer confined to countries or communities within countries, are not only across the entire globe, but also generations in time. So we have to look at equity in multiple dimensions across time and space and make sure that sustainable development becomes the framework in which we embed health equity.

Trends in Public Health I

Demographic and Epidemiological Transitions

As Bob Dylan sang, “The times they are a-changing.” As the cliché goes, change is the only thing that is unchangeable in this world. It is true that even in terms of public health and global health, we see change almost constantly. But there are certain driving forces which are responsible for the direction as well as the dimensions of the change. And it’s important that we understand them so that we can not only predict what is likely to happen, but also position our public health interventions so that we anticipate and avert some of the major public health problems as well as advance health equity in the desired direction.

The transitions that shape public health have been described by Rayner and Lang as demographic, epidemiologic, urban, and nutritional. These are traditionally seen by most public health experts as the important drivers of health transition. However Rayner and Lang also emphasize that there are others that we do not conventionally take into account but nevertheless are very important for understanding changes in public health. The economic transition, energy transition, the biological and ecological transition, cultural transition and democratic transition. Of these, the demographic transition is the most widely studied and most often discussed. This is where there is a transition within a country from high birth and death rates to low birth and death rates, along with the development from a pre-industrial to an industrialized economy. Warren Thompson developed this concept in 1929. And then he basically based it on the historical demographic observations in developed countries and later on this has been adapted to the study of developing countries as they are in developmental transition with accompanying epidemiologic and health transition.

In terms of demographic transition we are looking at five stages where in the earliest stage, which is high stationary, we find a fairly high death rate as well as a high birth rate on the population. And when we look at the population itself, because the deaths and births are canceling themselves out, the population growth is actually high stationary. Then we see a stage where the death rates start falling first and the birth rates continue to be high and therefore the population starts expanding. This is early expanding.

In the later stage we see the birth rate also beginning to fall but the death rate continues to fall fairly sharply and therefore we see a late expanding stage of the population. Then by the time the death rates and the birth rates both fall to low levels, where they reach approximately each other, the population growth becomes stationary and the population level remains stable. But then the birth rate continues to decline as in some advanced countries like Germany and Italy and there, because the death rates have now fallen to a lower level, but the birth rates are fallen even to a further lower level, the population starts declining. And that is where we find the fifth stage in some countries.

So there are several countries which are going through these phases and demographic transition therefore is an important concept in understanding how the age profile of the population, the size of the population, as well as the disease patterns of the population are determined. When we look at China for example, we see a huge shift in the demographic profile from a pyramidal shape in 1990 to a virtually, a cylindrical shape in 2050, where we see that the bulge is mostly in the middle and the top of the age profile, rather than at the bottom of the age profile where the young predominate. And we see also this happening in terms of life expectancy. As we understood previously from the millennium Preston curve, as per capital income rises, we find life expectancy rising up to a certain level and then gradually plateauing it off. And we found this in the case of China, where up to 1970, life expectancy rose very sharply as the economic development went in and also the social determinants like water, sanitation, nutrition were addressed in a very equitable manner across that society.

But then the population growth started stabilizing a bit and life expectancy also started plateauing off a bit. On the other hand, in India we are seeing a steady rise in life expectancy as we move from 1960 to 2010. And as a result of this, what we see is thatthe total fertility rate in China has fallen over a period of time. This of course in China has been accelerated by the one child policy. On the other hand, in India, we do see a falling fertility rate, but far less sharply than in China. As a result we see also a relatively delayed demographic transition in India in comparison with China. In China, the working age population actually peaked close to 2010 and is now on a decline in terms of the ratio of the working to the non-working age population. So China has already had its demographic window of opportunity when there is a large expansion of the working age population, which can give a thrust to economic development through increased productivity. India is still to have that demographic window of opportunity in terms of a rising working age population. This is beginning to happen now and we can anticipate an accelerated economic growth from this demographic dividend.

However, in order to harness this demographic dividend, India will have to invest both in education and skills for the young people, but also in protecting the health of the population. That is where public health becomes a very important element for economic development. Otherwise the demographic dividend can turn into a demographic disaster with a large number of working age people suffering from early death or prolonged disability.

The concept of epidemiological transition based on demographic change was originally propounded by Omran who described three stages. In the first stage where societies still experience a lot of pestilence and famine, the average life expectancy is about 35 years. And infectious diseases and nutritional deficiencies dominated that society. And later on, as people moved from a life expectancy of about 35 years to 50 years, the pandemic started receding and we started seeing the slow advent of non-communicable diseases like hypertension. But even those were substantially related to hypertension with hemorrhagic bleeding stroke. And we found that later on, in the mid-20th Century we saw the age of degenerative disease becoming the dominant epidemiological profile of a demographic transition. And in this, life expectancy rose to about 60 or above, but we found that by now the clotting stroke and ischemic heart disease or coronary heart disease became the dominant killers, infections receded, particularly major infections which killed people all across the world, became, less of a public health challenge. And even nutritional deficiencies were substantially corrected in several parts of the world. But this was a profile seen mostly in high income countries. Low income countries continued to experience some of the earlier phases of transition. And then we also had other transitions that were added on later in which we had a stage of delayed degenerative disease which is proposed by Olshansky and Ault, who said that by the time United States and Europe crossed the 1980s, we started seeing life expectancy cross 70 years, people still died dominantly of non-communicable diseases like ischemic heart disease, stroke and cancers, but many of them died above the age of 70 years. What we saw in Russia was a reversal after the fall of the Soviet Union where a stage of social upheaval suddenly came in in a period of transition life expectancy among Russian males fell to 58 years the lowest in the century because of the variety of reasons cardiovascular death rates went up, alcoholism became a major problem killing a larger number of people, and that actually can have a reversal of the epidemiological transition. But we can also anticipate that there could be an era of environmental degradation if we do not protect the environment on the planet.

And we do not know exactly what’s going to happen in terms of resurgence a of a large number of infectious diseases added on to the already existing problem of non-communicable diseases and how that is going to play out. We should try and avert that by protecting the environment. So these are the kind of transitions that we really ought to be looking at in terms of various developing countries and seeing the stages in which they’re transiting. But one of the important lessons is we don’t necessarily have to go through each phase for exactly the same length of time that the high income countries experienced. By utilizing the knowledge that we already have, we should try and telescope the transition by abbreviating the stage 3, where there are large number of mid-life deaths and move quickly onto stage 4, where even if people die of non-communicable diseases, they’ll die mostly after the age of 70 years.

This particular health transition model has been very helpful in providing an model for predicting what’s going to happen and understanding some of the dynamics. However, it’s been somewhat limited because it is focusing mainly on proportional mortality. While giving us an evolutionary perspective rather than a limited cross-sectional view, it is underestimating the burden of non-communicable diseases in countries of Africa for example where we see in Tanzania already the age standardized mortality rates of stroke in the age group of 15 to 59 far exceed those in England and Wales. But you don’t capture that by only looking at proportional mortality, because HIVAIDS, malaria, and others are actually killing a large number, therefore the proportional mortality due to non-communicable diseases appears to be lower. So the model that was proposed by Omran which is mainly based on proportional mortality, looking at the ratio of deaths from a particular cost to total mortality serves a useful purpose, but has some limitations. The other limitation is, health transition is not simply a linear model, because all of these are likely to be determined by complex interactions among various determinants. And these complex systems are nonlinear. So while we do depend upon the health transition model, the epidemiological transition model, we will have to look at other elements which determine global health. Some of these transitions can occur very rapidly. For example in Mexico we have seen between 1950 and even by year 2000, a massive increase in the deaths attributable to non-communicable diseases and a substantial decrease in the deaths attributable to infectious diseases.

So transitions are happening very rapidly because unlike the leisurely pace of transition that took place in Europe and America in the 19th and 20th Century, we are seeing the forces of rapid urbanization and globalization propelling countries in the low and middle income group into a rapid health transition with a very speedy rise of non-communicable diseases. And sometimes the coexisting burdens of infectious diseases and non-communicable diseases overwhelming the health system simultaneously as in the case of India.

Now in terms of nutritional transition. The traditional diets are now being replaced by western diet patterns. And there is an accelerating rate of change in diet, particularly through transnational trade, aggressive marketing of unhealthy food products. Simultaneously, there is a shift in physical activity patterns with a large number of labor saving devices at home and for transport. We now find that people are far less physically active. In fact this is the paradox of modernity that previously people used to be paid for doing physical work, now people have to pay for doing physical work. They have to actually become members of a gym. So we have seen a fair amount of changes in the nutrition profile across the world. But this pace is not uniform across the world.

For example in Asia, the number of undernourished people are declining as demographic and economic transitions take place. But in sub-Saharan Africa, there still continues to be a huge unresolved public health challenge. In terms of obesity however, we are seeing a rapid rise almost in every region of the world. And we are seeing that overweight and obesity are going to be one of the major public health challenges of the 21st Century, not only because they’re a problem by themselves, but they set the stage for a huge rise in non-communicable diseases like cardiovascular diseases and diabetes and cancers.

There are other transitions also that we must understand. The biological and ecological transitions. When we start deforesting and herding animals close together for increasing our meat consumption, we are also creating a conveyor-belt for vectors and viruses to migrate from wildlife and forestry into veterinary population and human habitat. As we alter the environment and create climate change that is also going to affect our health in very many ways. So understanding ecological determinants of health is becoming even more important in the 21st Century than ever before. Even in terms of energy security, this becomes very important. Because the pursuit of cheap energy is also shaped by the desire to replace human and animal labor. But as we move towards increased energy utilization we also have to see what it is doing to the environment, ambient air pollution, indoor air pollution, and also to see whether that is also transforming our life in terms of reduced physical activity.

All of these matter. And even energy security across the world has economic implications which in turn determines how health systems are funded. So all of these are going to be very important, because there are countries which provide huge energy subsidies. Can some of that be withdrawn by reducing the amount of energy dependency we have and the savings be transferred to health for universal health coverage? These are the kind of questions we ought to be discussing in global health in the 21st Century.

Similarly, democratic transitions are also very important. Because how much of  decisions are made in a country by the people at various levels? Are communities empowered? Are the provinces and regions empowered? Or is everything so centralized and dictated by a central authority with very little participation of people is going to be important. In the 21st Century democracy is moving from a representational model to a participatory model. Social media are becoming very important. And therefore a lot of public health knowledge is going to be disseminated and a lot of public health action is going to be driven by this kind of participatory democracy. So these are all trends that are going to be determining global health in the 21st Century. So when we look at all the determinants, we look at demographic shifts such as aging, urbanization and industrialization which alter living habits, globalization, which actually through marketing can accelerate a lot of changes in the way we live and education and culture which shape our beliefs, not in one community but across the global community and poverty which limits access to health both in terms of being a barrier for health information as well as health services.

And we are looking at urbanizing environments where the built environment can either be a barrier to physical activity or it can be an enabler or it can create pollution or provide clean air. And underlying all of these, there are also vectors like tobacco, unhealthy food and alcohol which are rapidly driving the health transition across the world and towards obesity and non-communicable diseases. Understanding these determinants is absolutely pivotal to global health in terms of its actions in the 21st Century.

So we understand health transition, but we need to respond to it. There are populations because of demographic and social determinants which are being propelled from low risk to high risk. Like rural populations, populations in low and middle income countries which are moving to westernized patterns of living in terms of food consumption, or tobacco consumption.

There are also.people in each country who are actually at low risk. Children, children are not born with a high risk. But the way we actually nurture them in our society can create high risk for them. So we need to provide these low risk populations from moving to high risk through public health interventions which create a healthy society.

At the same time in every population, there are individuals who’ve already acquired high risk. We need to return them to low risk by clinical and behavioral interventions. So while high risk may be determined by a combination of biology, beliefs and behaviours, there are a number of interventions that we have which can actually reduce the risk. And our public health interventions in the 21st Century must combine all of this knowledge into effective interventions both at the population level and at the individual level through competent health systems which take the lessons of health transition into account while framing global health policies and shaping global health practice.

Infectious Diseases V

Childhood Diseases with a Focus on Diarrhea and Pneumonia

In this next chapter I’d like to look at some childhood diseases that are particularly common in low-income countries and focus particularly on diarrhea and pneumonia, as they provide some very interesting examples of both how to prevent as well as how to treat these conditions so that the mortality and morbidity continues to go downward. The pie chart indicates the prevalence of each of these conditions in today’s world. You can see both diarrhea and respiratory diseases make up a large segment. And in some parts of the world, malaria is a major contributor as well. This is mostly in sub-Saharan Africa. Now here’s a child with a severe dehydration caused by diarrhea. Dehydration is the loss of fluid from the body. It’d be like if you took a grape and made it into a raisin or a plum into a prune. And you can see the child’s eyes are sunk back.His breathing would be deep and rapid. His pulse would be rapid. He’d have very little urine output. All signs of the loss of fluid and electrolytes. And here is a, a much younger child. And here you see the top of the head is depressed. This is called a fontanel, soft spot to many of us, before it closes. And here the dehydration has led to this sort of depression of the fontanel. Sometimes mothers would actually put mud or other substances there to try to draw this out, not recognizing that it might be due to dehydration. For a long time, in the summer months particularly through out the world, America, Europe and in lower-income countries you would see this scene in hospitals. Bed after bed after crib with children with diarrhea. And you could see here the dehydration, the loss of food and electrolytes are being replaced by I.V- intravenous solution. That’s fine if you have that solution, but in some parts of the world, this was very hard to come by. The IV solution wasn’t available or if it was available, it was expensive. You needed the tubing and the needle to insert and someone to do it. So there was a search for many years to find something that could be given orally, as this would eliminate the need or greatly obviate the need for interven…intravenous fluids. Now I show you this picture of a cholera cot, which is a wonderful piece of appropriate technology designed to be used with someone who significant diarrhea. And it’s simply a, a jute cot with a plastic sleeve that fits over it with a hole right where the buttocks would be. And that plastic sleeve goes into a bucket. So the liquid stool goes through the hole, through the sleeve, into the bucket. And one can then measure how much fluid has been lost. And the simple way of treating diarrhea is the patient gets exactly in what they have lost. And a way of measuring the level of hydration of course is whether they’re putting out urine and the concentration of that urine. Here’s a little girl who’s severely dehydrated. You can see again, that face that she looks. Again her pulse would be rapid. Urine output very low, rapid deep breathing. Now the mother is giving her an oral solution with the proper amount of electrolytes and glucose, that’s the magic ingredient. And to hydrate her. She’s alert enough to take it by mouth. And just a few hours later, here’s that little girl again and you can see a tremendous difference in the way she looks. The basic principle is simply this, a plant without water and you restore that plant by giving water and in the, in the case of diarrhea, electrolytes. Now what is the oral rehydration solution? It’s simply sodium chloride- table salt; sodium bicarbonate or Trisodium citrate; potassium chloride, and potassium is found in bananas and various fruits, citrus fruits; and glucose. Glucose is the key. And you can see on the other side that the sodium chloride, potassium bicarbonate and glucose are the millimoles per liter. In today’s solution, the sodium would be down to about 75 millimoles and the bicarbonate would be somewhat lower. And…. But that would be the major changes. Lower sodium chloride, slightly lower glucose and so on. But the basic principle and the basic composition remains the same. The message of course is to hydrate, hydrate, hydrate, because without the hydration other things can occur that will be a detriment to the individual, including circulatory collapse. To remind you, the…another side effect of continuous episodes of diarrhea is under-nutrition. Oftentimes because the mother will not necessarily feed the child, sometimes doctors recommend against it, unfortunately, and also the child may lose their appetite. Here’s a child who’s got severe marasmus. You can see the thin extremities. The child seems to be sensitive to light. The hair is thinning. And this is obviously a very poor family. Also the giving of a bottle of milk through the bottle can also be problematic if the water is not clean and if it sits out in the sun and bacteria are allowed to grow. Here’s a child who’s had multiple episodes of diarrhea and formula feeding. And you can see he has severe marasmus. So breastfeeding should always continue. And mothers should continue to feed their children if they have any appetite whatsoever, with whatever food is presently given to the child. So if the child wants to eat and the child is hungry, the child should be encouraged to eat. The teaching of this is best done of course in the community itself with three or four women who are taught now to prepare, shown how to prepare it and actually prepare it, which is what is being conducted here. You also notice lots of children around and these kids are picking up the message, just like their mothers are. And since children learn quicker than adults do, they’re going to carry the message into the community as well. One of the early tests of the oral rehydration therapy was in a refugee camp in 1971, refugee camps, where people from, refugees from what was then East Pakistan fled into West Bengal. And here they took up residence essentially in the pipes that were going to be placed in the ground to take away sewage. And when one lives in these kind of circumstances, you can guarantee that diarrhea is going to be a major problem unless there is strict attention paid to water and sanitation. And if that occurs then the treatment of this both in adults and children is essential. Another example of that is this is from a flood that occurred in Bangladesh. These occur periodically. This was 2007. And you can see individuals in an urban setting are trying to get clean water, even through a, a tube well pump which is almost totally submerged. This led to a major outbreak of diarrhea where up to 44,000 patients were seen at a treatment center within a nine-week period. What is interesting about this picture is that the family members are very much engaged in the treating of their loved ones. This is very critical because in these huge outbreaks it’s very difficult if not impossible for the medical staff to treat everyone. So one can engage family members who can be taught rather quickly how to deliver oral therapy and how to feed the patients and so on. And in that 44,000 cases, there was no one death from diarrhea and dehydration. This is a, an example of a packet that was found. This is for 500 cc’s which is now the standard in many countries. One liter is the standard in many other countries. So this, these salts can be given through a distribution scheme of these packets, as long as the packets are designed for whatever standard container people have. The next area I’d like to address is pneumonia, especially bacterial pneumonia, because this is what kills children. A number of years ago WHO developed what’s called an algorithm, a way of looking at pneumonia and deciding how to treat it given the severity. So in this particular algorithm you’ll notice on top that very severe pneumonia is defined as when the patient is confuse…cyanosis has set in. That is the child looks a bit blue, their lips look blue. They’re unable to drink. They’re unconsciousness, state of consciousness may be reduced. They’re clearly very, very sick. Severe pneumonia is when the lower chest in-drawing occurs and these children also need antibiotics. Where the respiratory rate is accelerated in the next box, going down, either above 50 is the child is two to eleven months or above 40 is one to four months, pneumonia is also the diagnosis. But if none of these occur, the child need not be treated for pneumonia. Now fortunately there are a number of vaccines that can prevent acute respiratory infection, many of which lead to pneumonia. Pertussis vaccine, diphtheria. Measles is a very important component, a very important vaccine. As is HiB conjugate vaccine, and the pneumococcal conjugate vaccine, two vaccines that have appeared on the scene in the last number of years that can make a significant impact on the incidence of disease. I put in meningitis because although it doesn’t cause pneumonia, it is a respiratory infection. Lastly I have this last picture in to remind us that malaria in some parts of the world can be a devastating disease to young children. This is simply an Aedes aegypti female, cause it’s only the female that takes a blood meal to help to grow her eggs. And you can tell the kind of mosquito by the white banding on the legs. So malaria can be a devastating disease to children, especially in low-income areas of sub-Saharan Africa. So what I’ve tried to do in the, in this chapter to point out that infectious diseases are certainly still with us and a major cause of morbidity and mortality, especially from diarrhea and pneumonia. But both of these conditions can be treated with oral solutions or I.V if necessary for diarrhea and antibiotics or other supportive measures for pneumonia. And both of them can be prevented through clean water and sanitation or vaccines, depending on the type of illness we’re talking about. The same by the way is true for malaria where the use of bed nets and early diagnosis can dramatically reduce the incidence of malaria, particularly in high incident countries.

Infectious Diseases IV

New and Re-emerging Infectious Diseases

Today’s chapter, is going to be on new and reemerging infectious diseases. Let’s again try to define these terms. Infectious diseases with an incidence in humans that have increased in the past thirty years or threaten to increase in the near future we tend to term new and reemerging infections. HIVAFRICANow new infectious diseases that have come about in that, roughly in that time period would include HIV/AIDS, SARS, Lyme disease, Nipah virus, influenza H5N1 or H1N1. Infectious diseases are however often times emerge in new places and they are sometimes called reemerging diseases. This would be diseases such as West Nile virus and monkey pox. Then there are diseases that reemerge in drug resistant forms. A particularly worrisome group which includes malaria, multiple drug resistant tuberculosis, and some bacterial pneumonias and sexually transmitted diseases. Now there are a number of factors that have contributed to the arising of new and reemerging infectious diseases. These might include increased population density, inadequate infrastructures for water and sanitation, movements of people through travel and social disruption, the centralized production of food and it’s distribution, environmental changes, misuse and overuse of antibiotics and other drugs, changes in human behavior and sometimes dysfunctional governments. Let’s look at some of these in greater detail. In terms of the increase in population it was estimated that the population in 2000 was about 6.1 billion people and by 2050 this will come close…become close to doubling to 9.4 or 11.2 billion people. We’re also seeing a tremendous increase in urbanization going from 47% in 2000 to 60% to 65% increasing urbanization of the global population. Now as the population of the world increases of course there are going to be greater contacts between humans and wildlife in habitats that normally we don’t venture into and because of this interaction with both humans and our animals, we may see the rise of new viruses. The coverage of water supply, particularly in least developed countries, is also very problematic.

HIVContagioParticularly in both urban and rural areas in least developed countries the percentage that have access to potable water is anywhere from 50% to 60% Most of the drawing of water in rural areas and in urban areas is work of women. That is, they are the ones who are doing all the work of getting it from wells, from rivers and so on and taking that water back to their home. This is assuming that there is not an indoor water tap. And in this, the bringing of water into urban areas through trucks and so on where people are then forced to come to this area, collect the water, take it back to their home, is another way of distributing but it’s also very problematic as that source could be contaminated as well as the buckets and vessels which carry the water back to the home could also be contaminated. It also limits the amount of water that’s oftentimes available. The disposal of human waste is an increasing problem. The privies are directly linked to a body of water which connects to other parts of the city and that…that fecal disposal is of course quite unsatisfactory. We are increasingly discovering that open defecation may well be linked to under nutrition in children where this is a broad problem. The increase in travel both internationally and locally also provides opportunities for diseases to move about. We can move Ebola from one country into another in a matter of a few hours by air and we have seen this…this happen. No place in the world is unconnected to any other. We are really truly a global village. The production of food on an industrial basis has allowed for increasing availability of food, both grains and meat, but has also intensified the use of antibiotics and the raising of animals and where a central food supply is contaminated that contaminated food then travels far and wide. It’s not the same as getting milk from your local farmer or buying vegetables at the local farmers market. When we buy vegetables and fruits in many of our large cities of the world we have no idea where this comes from. Here’s the production of chickens in an industrialized production where thousands upon thousands of chickens are grown together in oftentimes extremely inhumane circumstances where they have no movement and so on and one can see that where a disease would enter this population it would destroy many, many chickens in a short period of time. This is of course quite different than what takes place oftentimes in local areas where there may be one purveyor of chickens from a few individuals in the community. Where ecology is involved is of course in climate changes, where temperatures have increased in certain areas which have allowed for the introduction of mosquitoes for example that had not been there in the past.

processosdecontagioThe tires are often traded internationally but when one trades in tires, there’s oftentimes water that is in the bottom of the tire and those…that water will you don’t need much to set up a breeding ground for mosquitoes. Those mosquitoes can then carry the viruses from where they came from to where they are going. And then the misuse of and overuse of antibiotics has led to the development of antibiotic resistance. We have only had antibiotics really for about 70 years. A blink in the eye in terms of evolution and yet we have managed to create a number of organisms that are extremely difficult to treat and far more expensive to treat. For example, multiple drug resistant tuberculosis is much more expensive to treat than is regular tuberculosis. Artemisinin which is the last, the latest drug we have to treat malaria, the last in the line, resistance is developing to that even though we treat these…malaria now with three drugs to try to avoid resistance to artemisinin. Tetracycline for cholera, multiple drug resistant gonorrhea which is a problem and in our hospitals, multiple drug resistant staphylococci which can infect wounds and cause devastating diseases. I would now like to focus on one particular new disease that has taken the world by storm over the last 30 plus years and that’s HIV which leads to AIDS. One might ask, where did HIV come from? Now is it a….. It’s defined as a new disease. It most likely came from somewhere in sub-Saharan Africa. There is a, an infection in some of the great apes, simian immune deficiency virus. It might well have been that someone in the forest or in a market was skinning a, a chimpanzee or a related species and cut themselves with a knife that carried the blood of this animal and therefore infected themselves. And unfortunately this virus adapted itself to humans. It then spread from that person through sex most likely, but it could have been through other means to another person and so on, until there was a critical mass of individuals who were infected and then the epidemic gradually increased. And then of course spread globally over time. We don’t know the initial events but it would seem to be that this was a zoonosis where the organism adapted itself very effectively to human beings. The distribution of HIV even though it came upon the world within probably five or six years it had been introduced everywhere, you can see that the distribution is of quite variable with most cases occurring in sub-Saharan Africa and if one looks at the population to case ratio, it’s even higher in that part of the world. Which raises an interesting question: why though HIV appeared in the world in many parts of the world around the same time, why has the spread been heterogeneous, not only globally, but even with the epidemic in sub-Saharan Africa? And I’d like to explore those ideas for just a moment to look at why this might happen and what does it tell us about prevention of these conditions? Now the spread of HIV in sub-Saharan Africa between 1984 and 1999 was quite interesting because it in 1984 it was fairly evenly distributed. By 1999 this had become a disease much more in the very southern parts of Africa and eastern Africa and West Africa in some parts have remained somewhat unchanged, Senegal, Mauritania, Niger, and so on. The dark red represents the highest prevalence of HIV. Now there are certain risk factors, I’ll call these proximal determinants that are associated with HIV/AIDS, the getting of…the obtaining of this infection. Clearly transfusion with contaminated bloods or contaminated needles and syringes which is like a mini-transfusion. Unprotected sex with a single or particularly multiple partners can increase your risk substantially. Mother to child transmission through delivery and breast feeding and interestingly the non-circumcision of men in certain parts of the world. Let me look at that last issue. Male circumcision interestingly enough is probably one of the oldest forms of surgery going back to at least 2200, 2300 years before the common era, as seen in this hieroglyphic from ancient Egypt. The circumcision rates in different countries in sub-Saharan Africa you can see are quite different with the highest level of…of AIDS in those countries which have the lowest level of male circumcision. Now why…why should male circumcision protect one? Well, it turns out that the inner lining of the foreskin contains cells which have a particular avidity for the HIV virus as well as the human papillomavirus which is associated with cervical cancer. Also when one removes the foreskin, the skin underneath hardens a bit and is more impenetrable probably to the virus itself. So there are biological reasons for why this particular simple operation reduces risks. We should remember that the initiation or the institution of…of male circumcision which by the way has nothing to do with female circumcision, was related to tribal or religious identity. It was not initiated initially to as any type of health measure. Certainly we didn’t know about these issues hundreds of years ago when these practices were introduced. Now distal determinants, that is those factors that affect the proximal determinants would be socioeconomic conditions, domestic violence, the status of women, the degree and type of migrant labor, sexual practices and values as defined by culture, and we have to be very careful that we don’t associate practices and values with any kind of ethical or moral character of the individuals involved. They have their antecedents in other…in other issues. And then concurrent partnerships. This is having many partners over a week as they have…having those many partners serially over the course of a year. Now what strategies then can we use based on these risk factors to reduce the possible risk for HIV? Well, if we delay the age of sexual debut that is when adolescents begin to have sex, we clearly reduce the time when they’re going to be exposed as we would be reducing the number and the exposure to high risk partners. If we reduce the degree of concurrency that would also reduce risk. If we limit alcohol and drug use prior to sex we make sure that the inhibitions to using condoms for example are not taken away. We can increase the level of male circumcision where the rates of HIV are very high and this would be again very much in southern Africa but not in…and East Africa but not in many other parts of the world. We could presumptively treat some sexually transmitted diseases to reduce transmission and certainly test the blood supply and needle exchange and syringes for I.V. drug users. One could also treat individuals who are HIV positive and thereby limit the transmission of this to their partners. This is problematic however and is not as easy to implement. If one looks at this schema of the HIV infection, one will notice that the first few weeks, months is when we have the highest level of viral particles in our blood, viremia. It is during that period of time when one is most likely to transmit the infection. So if one has a number of partners during that time, has sex shortly after one is infected, you are more likely to transmit the infection than when you enter the asymptomatic period which can go on for a number of years. Now we can measure the viral load in the blood and we can also look at other associated factors such as the CD4 count but it’s those first few weeks, months maybe, that we are most likely to transmit the infection because we don’t know we’re infected. There is no way of telling other than to do frequent HIV tests which is somewhat impractical. We can also reduce the risk of infection post exposure. That is, if someone is exposed, we can give nevirapine for the transmission, to reduce the transmission of mother to child. We can treat with ARVs as I noted post exposure or even give it prophylactically especially to high risk groups, people who have multiple partners for example. The use of vaginal microbicides has also been recommended but these are the factors that you can do post exposure. Clearly it’s far more practical if we can prevent the infection to begin with. Well, what I’ve tried to do in the…in this brief chapter is to look at new and reemerging infectious diseases. Why they occur, what are the risk factors in the modern day world. I then focused on HIV/AIDS as an example of a new and reemerging disease.

Infectious Diseases III

Zoonoses

In this next chapter I want to take up the subject of zoonoses. Zoonoses is an infection or an infectious disease that is transmittable under normal and natural conditions from vertebrate animals to humans. It may be enzootic or endemic or epizootic or epidemic. There’s also another term, zooanthroponosis which is a disease transmitted from humans to animals. Now there are different types of transmissions with zoonoses. There is direct transmission, that is intimate contact with an infected animal, a person such as with a bite, a scratch, a spray by infectious urine, contact with fecal material, inhalation of a discharge, respiratory droplets due to coughing or sneezing, airborne spread, this is direct HIVAFRICAtransmission. Then there is indirect transmission where there is an arthropod vector such as a flea, a mite, a mosquito, a tick and fomites such as cockroaches that are contaminated with the particular product going from an animal to a human. Another term we should be familiar with is species jumping. This is the transmission from animals to humans followed by human to human spread and this is the group that we are most interested in. That is, we shall see with HIV/AIDS, with SARS, with flu, that the particular agent went from an animal to a human and then began to spread from human to human. So the first one I’d like to take up is SARS or severe acute respiratory syndrome. If you’ll recall, this completely paralyzed the world a number of years ago because the mortality was quite high from this. Well, it turns out that SARS as we found out much later on was due to a particular virus called the coronavirus which was found in a particular animal called the civet cat which was slaughtered in some of the markets of…of China. But these civet cats had in fact been infected by bats, so it was bats that had the coronavirus, it infected the civet cat, the civet cat when they were killed, the spray of blood, sometimes people inhaled, they got it and they were then able to transmit it to other humans and it led to a type of pneumonia and if you’ll recall there were often pictures such as this from China, which is where the disease particularly had a major impact although it then spread to Honk Kong and Singapore and Canada and to Vietnam and so on. It never became the global pandemic that some of these conditions can become.

ebolaThis is the latest of pandemics, this is the Ebola virus. Many of you have heard about this. It’s been particularly devastating in West Africa in this recent outbreak but it has occurred in central Africa as well, and let’s take a look at this particular virus which has been considered very contagious thought not very infectious. That is it can spread from one person to another through contaminated feces and blood and so on but doesn’t spread from person to person in a crowded room for example. It doesn’t spread through the aerosol route but rather through the blood and feces and so on of individuals who are infected and sick. They have to be sick with this disease. Here are some of these workers carrying…wearing these gowns to prevent them from having contact with this particular virus. This virus has probably, though we’re not sure, been spread by fruit bats, that is the bats again carry this particular virus. The bats may have contaminated food that was then eaten by an individual and that individual developed this disease, Ebola, and then spread it to other people through their bodily secretions. But it was the bat that originally harbored this virus, and then spread it, gave it to people and it was through the person to person spread that it has taken off. Let’s take a look at another one of these zoonoses. This is one called Nipah virus. Quite interestingly, again, this giant fruit bat and why they harbor these viruses we’re not sure and it’s very uncommon actually, would eat some of the fruit of these trees in Malaysia that were planted in areas where pigs were…pigs were grown. The pigs ate the fruit that fell to the ground and because this fruit was contaminated by the virus, the pig in eating the fruit developed an infection. When these pigs then were taken for slaughter and killed by, in the Abattoirs, the slaughterhouses, the men who were involved in this in the pig killing got the infection from the pig. So it went from a bat to the fruit to the pig to the people who were killing the pigs and up to 250 people about developed or died from this condition, a mortality of around 40% or 50% and this occurred in 1998 and 1999. And to get rid of this particular condition, first of all when the pigs became sick the first thing people did is they took them to market, so oftentimes these sick pigs, and they had developed a pneumonia, were taken to market and people would buy it unsuspecting that this might be this particular condition. And the way that Malaysia eventually got rid of this Nipah virus is they took pigs and they killed them and there is no longer a pig industry in Malaysia where at one time it was quite flourishing. This now takes us up to Bangladesh and in Bangladesh there was also an outbreak of Nipah virus and they couldn’t figure out how did this virus get into the human population. Because there were no pigs in that part of Bangladesh. It was a predominantly Muslim society and pork was not eaten, but they pieced together a story that showed that when these bats went to this date palm juice…now here’s a pot on a palm tree that is collecting date palm juice which is a sort of sweet juice that can also be made into something called gur which is a type of sugar. And when they would lick this because they’re fruit bats and it was very sweet and sometimes they would defecate into the pots. The men who sold this and this date palm juice was considered quite a delicacy would take it from house to house and sometimes this date palm juice was contaminated and individuals who took it would get Nipah infection and the mortality again was around 40% or 50%, sometimes 60%. This was a meningoencephalitis, that is it affected primarily the brain. Here are some bats flying just at dusk and they’re quite large, they have a large wingspan but they only drink fruit and sweet things. So the way to get rid of this was to put a skirt of bamboo over where the…the sap came from the tree into the pot and by doing this you can actually reduce the contamination of the date palm juice because the bat can not have access to that…to that sap that’s coming from the tree. So again a bat to the fruit, contaminating that, humans ingest it and it can spread from one person to another on…only on very, very intimate contact. And this is only through respiratory droplets, so it’s not like someone can walk into a room and cough and others would get it. You have to be extremely close to the individual to get this particular infection. So how do we control the transmission or the introduction of zoonoses? Well, this diagram here shows the linkage between wild EID is emerging infectious diseases, domestic animals and humans. And you can see that they interact. Now I’m not going to go through this entire graph but let’s just take a look at a few of the linkages. The linkage, say between wildlife and domestic animals. Here if domestic animals are closely associated with certain wildlife as we saw with the Nipah virus in Malaysia, there’s a spillover effect and these domestic animals can pick up the infection. If we look then down to the bottom of domestic animals and look at the food processing technology industry, we see that this virus got into humans through the infection in pigs which was then picked up in the slaughterhouses and then in humans it spread from person to person. So we have to break…break a number of these links between wildlife and domestic animals, between domestic animals and humans and even between humans and wildlife and so a lot of the strategies that have been developed to control zoonoses have focused on this type of diagram that we see here. All or most of the new and reemerging diseases, not all, will in fact be related to zoonoses so zoonoses are clearly very, very important and extremely costly. Bovine spongiform encephalitis or mad cow disease costs the U.K.  over $9 billion in lost revenue. The Nipah virus which I just talked of cost Malaysia $540 million because of all the slaughter of pigs that had to take place. SARS which we started with cost China upwards of $50 billion because of the lost revenue from trade and tourism and so on and avian flu, H5N1 which we have not covered is going to cost billions and billions of dollars. In fact, another type of flu, H1N1 or what was called unfortunately swine flu, this is just a picture of the economic impact it had in Mexico where this beach would be filled with tourists at a particular time of year and of course it’s empty now because people are afraid and go elsewhere. What I’ve tried to do in this brief time is to talk about the importance of zoonoses. That is the diseases which linked animals to man and how they can spread, how they develop, SARS, Nipah virus are but two examples and there are many, many others. And then how they might be controlled and the economic impact that they can cause. We must be prepared to put much more attention into zoonoses and there is a global program called One Health which is trying to do just that.

Infectious Diseases II

Control, Elimination, Eradication, Extinction.

In this chapter I’d like to look at the control, elimination, eradication and extinction of infectious diseases. Again, let’s look at some definitions here. By control we mean the reduction of the prevalence, that is the number of cases at any one time, incidents, the number of new cases over a period of time, to locally acceptable levels which is usually interpreted to indicate no longer a public health priority. Intervention however is still required. Elimination is the reduction of disease to zero and or infection to zero. The intervention, however, may still be required. An eradication is the permanent reduction of global, we’re now talking about the whole world, incidence of disease to zero with the organism not present in nature. No intervention at this point is required. And now let’s take a look at some of these terms as they play themselves out. The criteria for eradication which is the area I’m going to focus on in a moment is that humans are the only reservoir and there are no non-human vectors. Now we’re talking about eradication in people.The absence of a carrier state. That means that people don’t carry the organism even though they’re not sick. The feasibility of the intervention, is it effective? Is it acceptable? Is it affordable? Do we have ways to monitor whether this infection is present in the community, surveillance? Are people concerned and fearful enough that they will buy into these programs and does government have a strong enough commitment to try to eradicate a condition? Now infectious diseases that have been eradicated, there is only one and that is smallpox. And this was done primarily through a vaccine. Other infections that have been pretty much eliminated from many countries are guinea worm, which is only now found in some parts of sub-Saharan Africa, neonatal tetanus or the tetanus of the newborn. Again, vaccines here. There are still some cases but not very many even though the tetanus bacilli exists in the ground around us. Polio, we’re very close to eradicating this through vaccine but there are still cases in some parts of Africa and South Asia. Diphtheria, these have come way down, as has leprosy. The…but again, smallpox is the only human disease that we have been able to eradicate. There is a disease in cattle called rinderpest that has been eradicated, but this is the only one for humans. This is what smallpox looked like. It was a terrible disease. This child has lesions all over the body, it sometimes would in addition to causing a lot of deaths, it also caused blindness, and many other complications. This was a typical picture of a smallpox case. I’m now going to talk about the vaccine that was developed to deal with this. It was noted by Edward Jenner, a practitioner in rural England, that cow…that women who milked cows, cowgirls I guess you’d call them, did not get smallpox and he noted that on their hand was a lesion that was gotten from the cows that they worked with which was cowpox. He reckoned that if it protected these  women and he took this from one woman who milked cows, Sarah Nelmes, that maybe this would protect people against smallpox. And in fact, he tried out the first vaccination was in 1796. Now prior to this, people had taken the serum, the lymph from the smallpox lesion of very mild cases and gave it to people hoping they would also develop mild disease. Sometimes it worked, sometimes it didn’t. Now despite the fact that this was shown to be extremely effective, there was a lot of resistance against this. This is a picture from a British publication, a humor publication called Punch and here is Jenner in the middle and people have cows growing out of their arms, their back sides, their face and so on. People figuring if they got the cowpox they might even turn into cows. Now, smallpox actually had eradication potential. What was that? Well, going back to those earlier criteria, there was universal fear, there was no animal reservoir, people were the only ones who had this disease. Nobody was a carrier, there was lifelong immunity after a single episode and a characteristic rash. There was no transmission from subclinical cases, as there were none. And we had a very, very effective heat stable ‘ (We didn’t need a refrigerator) vaccine and we had the development of a needle called the bifurcated needle which allowed us to easily transmit the vaccine to an individual. We also developed a very effective way of searching and containing this because smallpox moved relatively slowly through populations, once we found a case we could immunize around it so the case would be the orange circle there, we could then immunize around it, that would be the purple, and then we could also immunize the contacts of the contacts by taking these circles and moving out in this ring vaccination area we could reduce and eliminate smallpox from areas without having to immunize absolutely everybody in the population. We also minimize adverse events and we found that this vaccine was highly efficacious in preventing disease. The last case of…major case of variola minor occurred in Bangladesh in a young girl, Rahima Banu in 1976 and in 1977 the last case of variola minor appeared in Somalia in Ali Maow Maalin who just died recently. He devoted much of his life to also dealing with other disease elimination and eradication programs. The next disease I’d like to address is polio. Here are some children, we don’t see this very much anymore, because polio has almost been eradicated and has been eliminated from almost every country of the world. These children would develop paralysis, primarily in their legs, and in some places they would have to be beggars unless there was some way of looking after these children. In certain cases the disease affected the bulbar region of the brain and people would have to be on respirators, sometimes for lifetime because they could no longer breathe on their own. But with the polio eradication campaign globally we are down to now hundreds of cases rather than hundreds of thousands of cases. Getting those last few cases of course are extremely difficult so we can not say that this disease has been eradicated but it has been eliminated from probably 98% of the world. This is a very inexpensive, very efficacious vaccine. This is the oral vaccine. There’s also IPV which is an injectable vaccine but it is more expensive. If you look at the polio incidence by month, just in a four year period between 1994-98 in India, you can see that it was very high in 1994, peaked to over 110,000 cases, then came down in 1995 and at the end of ’95 and the beginning of ’96 they had national immunization days where they gave the vaccine to every child under a certain year. I think under five years of age. This was repeated again at the end of ’96 and ’97 and again at the end of ’97 and ’98 so that the number of cases came down dramatically. In fact, India has now been declared polio free and it has been eliminated officially from this country, which is a huge undertaking given the population of 1.2 billion There are other infectious diseases that have decreased dramatically in incidence, that is the number of new cases, with a significant reduction in mortality and morbidity. Measles is one of these which is a major killer, was a major killer of children. Rheumatic fever which affected the heart, hepatitis B which sometimes leads to liver cancer, and also peptic ulcer and helicobacter where treatment of these conditions with blockers of stomach acid and antibiotics has greatly reduced the incidence of these conditions. Here’s a child with neonatal tetanus, a condition which we rarely see today and that’s because now mothers are immunized against tetanus and they pass this immunity on to their child until that child can be immunized themselves. And lastly here’s a picture of measles which has been up until recently a major killer of children in low and middle income countries. So what I’ve tried to do in this last chapter is to review for you control, the terms control, elimination and eradication. I haven’t dealt with extinction because extinction means that there is no presence of this organism anywhere in the world and most of these organisms exist still in some laboratories. I’ve shown you eradication as it occurred with smallpox and the efforts that are going forward with polio. And lastly we’ve looked at a couple of diseases that have come down dramatically in their incidence and prevalence in the world.

Infectious Diseases I

The Changing Patterns of Infectious Diseases in Time and Place

In this lecture on infectious diseases, I’ll be covering a number of topics in the various chapters. This first one will be on the changing patterns of infectious diseases in time and place, that is looking at infectious diseases in a somewhat historical context.

I’ll also be covering the control or eradication and elimination of infectious diseases, 31infecaonos individuoszoonoses, emerging and reemerging infections, and lastly diarrhea and respiratory diseases in children as they are a major killer in this group of individuals.

Before we get into this historical look I want to give you some common definitions. What is an infectious disease? It’s a disease caused by the entrance into and growth and multiplication in the body of…of an individual of bacteria, Rickettsia, viruses, parasites, protozoans, fungi and prions. All of these are considered infectious agents. Another term which we should become familiar with is incidence. This is the number of new cases that occur per unit time. That time could be a day, a week, a month, a year. But time is very much a factor here. Prevalence on the other hand is the number of cases that occur at any one moment in time, today for example.

31processodeinfecao

I’m going to give you an extremely abbreviated history of epidemics, that is a large number of cases occurring, although that number could be just one. And pandemics which are epidemics that cover the global world. Diseases associated with many of these epidemics include plague, smallpox, influenza, cholera, yello fever and measles. Now some of these are more historical because they don’t occur today, especially smallpox and plague and yellow fever, but they are important. An example of a devastating pandemic was the black death from plague that peaked in the 1346 to 1350 time period and it was estimated to have killed 30% to 70% of European population. Smallpox and tuberculosis, killed up to 90% of the indigenous population of the New World when they were introduced by the Europeans. Cholera pandemics began in 1816 and now take up, we’re in the seventh pandemic worldwide.

doencascriancas1The largest single pandemic was that of the 1918 influenza pandemic which led to between 75 million plus deaths worldwide. These infectious diseases can be noted in history where they left their mark. For example in this mummy Ramesses V dated about 1157 BC we can see evidence of smallpox lesions. The pandemic epidemic that I want to focus on in the next pictures are those of plague. Plague was so common and was such a killer in Europe that there were dances of death that were developed to deal with the large numbers who were dying in various communities. This is a picture of a bubonic plague from one of the Bibles and we would probably not find these lesions to be consistent with plague today but this is the way people saw them. Doctors would oftentimes have very little to offer and would go around in these long black coats wearing these masks shaped like that of a bird’s head which limited the air that they would breathe in since they believed,in some cases correctly, that the miasma- the surrounding air, is what caused these diseases to occur in populations. People were so afraid and felt that the devil had entered their body and that’s why they would get these diseases that people would go around the countryside flagellating themselves to try to get rid of these evil forces and to show that they were deeply religious. Unfortunately, one of the things that often occurs in any epidemic or pandemic is we tend to blame the most impoverished, the poorest people who are there as we see them as the ones that have caused this to happen. And of course this is oftentimes very untrue. Jews who were burned alive because they were thought to be the cause of the Black Plague.

Oftentimes people were labeled as witches, as other non-desirables in populations and so that if we got rid of them, the plague would go away. Of course we even do this today and we’ve done it today with HIV/AIDS and other similar types of pandemics.

This is the organism that causes plague. This is called Yersinia pestis, it’s shaped a bit like a safety pin and these are transmitted through these fleas. Obviously not this large

but these fleas live on the body of rats, Rattus rattus and so oftentimes when there would be a rat die off these fleas would escape and then bite humans causing the plague. Sometimes there were large numbers of rats because the cats had been killed in some communities because they were seen as the animals of the devil. In addition to the tremendous number of deaths that occur, we also have to look at the historical changes brought about by any large pandemic. For example in the Black Death there were huge demographic changes. With 30% to 70% mortality in many areas of Europe, which took at least 150 to 250 years to recover. There were labor shortages, serfdom disappeared, wages became higher, labor saving technologies developed because there was a shortage of labor, land became plentiful, see these were all actually positive outcomes, despite the high numbers of death. However religious intolerance and the tradition of blaming others also increased and this was a time, oftentimes of religious intolerance that went through the countryside. Let’s go back to the terminology that we started talking about. If one is exposed to an agent, an infectious agent, a number of possibilities could occur. That is nothing, there could be clinical infection, the second line, or sub clinical infection or the person could carry the organism but not be sick. For clinical infection, one could see that death might occur, immunity that is what that an individual recovering from the disease might be immune or they might carry it or they might be non-immune and for the sub clinical infection of course there wouldn’t be death but immunity, carriage, and not-immunity might also occur. Also there are a number of factors that influence disease transmission and we should be aware of these. One is the agent itself which is the bacteria, viruses and so on. How infectious is it? What kind of illness does it cause?

What leads to its survival or death? Then there’s the host which is humans or animals, our age, our sex, our behavior, our nutritional status and so on, our health status, and then there’s the environment in which we live. What is the weather like? The housing? How crowded are people? What is the geography and what occupations do we have at the time that make it more susceptible. What’s the quality of the air, the food, our socioeconomic status and even the political nature of the situation. Now again, when something infects an individual there are a number of outcomes. An individual becomes infected and then there’s an incubation period which then leads to clinical disease or no disease. When somebody is incubating that infection, that is they’re not sick but that it’s growing in their body, there is a latent period. A period when they’re not infectious at all. They can become infectious, even before they get clinically ill, and it is during that infectious period that they can infect another. So you see in the first patient there’s the incubation and clinical disease, a latent period, in infectious period, and during that infectious period they infect the second patient.

This gives you an example of how infectious diseases have changed historically. In 1909 the percentages of infections in Chile causing mortality and morbidity was about 50%. Fast forward to 1999, those figures are now down to about 22%…23% so in 99 years, or in 90 years, we have seen a dramatic reduction in the importance of…of infections as causes of mortality and morbidity. We’re going to look at what we can do to reduce the importance of infectious diseases. There are a number of basis of infectious disease control. One, what is the quality of water and sanitation? What kind of water are we putting into our body? And how do we dispose of human waste and other waste? What about improved hygiene, hand washing for example. Housing- By decreasing crowding we can decrease diseases like tuberculosis. Improved nutrition also has a bearing because the host is stronger and able to combat certain infections. In the last 70 years or so we have developed incredible array of vaccines and antibiotics or antimicrobials. And lastly there have been certain behavioral changes. Here’s a young girl in a program that is teaching kids the importance of hand washing and how you can use soap and water to reduce risk, particularly after…after going to the bathroom for example. Unfortunately in crowded cities in many low income countries waste disposal through these latrines which are over-hanging a body of water in which kids sometimes swim and which are right across from a better off section of a city also leads to environmental contamination and increases the risk of the transmission of infectious agents. Far better that if we could put even this simplified form of a SanPlat latrine which people could use to get rid of waste rather than putting it directly into the water as shown earlier. Going back to vaccine development, the first one was in 1796 where Jenner used cowpox to in fact protect people against smallpox. We’ll see more of this later. In the 1800s we then had the development of rabies, cholera, typhoid and plague vaccine, but the huge increase occurred in the 1900s with diphtheria, pertussis, BCG which is for tuberculosis. In the 1950s we developed poliomyelitis vaccine and then in the 18…1980s, ’90s and to the present day there’s been a huge development in vaccines such as hepatitis A and B, pneumococcal rotavirus, meningitis, et cetera. The first antibiotics interestingly enough, this was not the first but one of the first, go back really to the late 1930s with sulfonamides but here is streptomycin, 1943 it was developed by Selman Waksman and first given to patients in 1944 for tuberculosis and you can see from this list of tuberculosis drugs that at least seven, and there are many more actually that have been developed since that first…since the first discovery of streptomycin. We now have other anti tuberculosis drugs which are used particularly against the drug resistant tuberculosis strains. Now lastly, I want to go back to our examination of the basis of infectious disease control and indicate a few other measures that we can use. One of these is surveillance and reporting, that is who is getting the disease, where are they getting it, and so on. So that we can then institute certain disease control programs, be it against malaria, other vectors, parasites. And we can institute preventive measures such as the promotion of hand washing, screening, education in schools, behavior modification, social marketing and so on and lastly the development of early and effective and affordable therapy to deal with the infections that are…have occurred in the past and will continue to occur into the future. So in this first brief lecture, I’ve tried to give you a few definitions of infectious diseases and how they might be transmitted. I’ve tried to look at the history of one of these, that is bubonic plague and pneumonic plague, and lastly to give you a brief outline of some of the basis for infectious disease  control.