Welcome. Today we're going to speak about emerging and re-emerging infectious disease and antimicrobial resistance. By the time you finish this session, you should be able to speak comfortably about the definition of emerging and re-emerging diseases. And anti-microbial resistance. Some examples of emerging and reemerging diseases and of anti-microbial resistance. Factors that contribute to the rise of these diseases and anti-microbial resistance. The health and economic costs of these problems. And measures that can be taken to address emerging, and re-emerging infectious diseases, and antimicrobial resistance, more effectively. Now, let's start by talking about some definitions. It's important to understand, and some examples. The new diseases have appeared throughout history. Bubonic plague for example was first recorded in the 6th century. More recently some other diseases have emerged for the first time including those shown on this graphic. Here what we have is the year of the outbreak. The name of the disease and the place in which they occurred, and these are emerging diseases. These are diseases that occurred for the first time in human history in these years. These included for example at the time, Marburg, Ebola what you know of as Mad Cow Disease. H5N1 virus, Nipah virus, severe acute respiratory syndrome, and Middle East respiratory syndrome. So let's keep in mind that an emerging disease is a disease that has appeared in the population for the first time. A disease is considered to be re-emerging or re-emerging infectious disease when it reappears after a significant decline in incidence, spread to new places or emerges in a new form. And the next graphic shows some selected examples of re-emerging infectious diseases. Although I have to say in some review that I was doing recently I see that people are I think using the term re-emerging less than they used to before. They seem to be speaking more about just the emerging but more traditionary they've spoken of emerging as new and re-emerging as those that have come back, come back in a different form. And here we see some examples of re-emerging infectious diseases with the year of outbreak, the disease, and the place in which they occurred like the Plague in India in 1994, Human Monkeypox, Dengue, and Ebola most recently in West Africa. Now there are a number of factors that contribute to development of emerging and re-emerging diseases as shown on this graphic. And I'm just going to highlight a few of them. [BLANK AUDIO] Clearly we're living in a world in which population is growing and more and more people are living in places in which they didn't live before. They're putting more and more pressure on the environment in some places. Many of these emerging diseases are zoonotic in origin, they come from the transmission from animals to humans. And human demographics and behavior, and the way we live, how we're living, how close we are to animals, can have an important impact in enabling the development of emerging infectious diseases. And this goes along, of course, with several of these. We also are living in a world that's more and more global, where there is more and more commerce. And where more and more food stuffs, animals, and people are travelling all the time. And if one has an outbreak for example of SARS in Asia, it wouldn't be a surprise if people with SARS didn't wind up visiting some other places and helping to spread that disease to those places as well. War and famine take an enormous toll on people, on the environment, on the circumstances in which people live and they can contribute as well to the emergence and reemergence of infectious diseases. As systems break down for example to try and treat them or prevent them in the first place. And sadly we're living in a world as well in which some people may wish to use biological agents as a weapon of war for weapon of terrorism. Much more could be said about this, but it is important to understand some of the factors that relate to the emergence of these diseases. Keeping in mind again, that so many of them are actually zoonotic in origin. Resistant forms of disease can also emerge or re-emerge when bacteria, parasites and virus are altered through natural selection or the exchange of genetic material. It's a natural process that they should develop resistant forms of disease. And in fact we know that there are any number of diseases in which such resistant forms have developed. Malaria, the drug of choice for malaria at one time was choloroquine. Choloroquine is not so effective right now. I think there are only a few settings in which it is still effective, and the drug of choice now is called combination therapy. There's another drug that was commonly used for Malaria and the Malaria is now much less susceptible to that as well. Tuberculosis is a disease of great importance, it's now the leading infectious cause of death in the world. Tuberculosis is now the leading infectious cause of death in the world. And recent estimates suggest that about 0.5% of all of the cases of active TB disease in the world are drug resistant. And in fact we find many different forms of bacterial infections that are now no longer susceptible to the drugs that were previously used to treat them, such or MRSA or Staphylococcus Aureus. So again the development of resistant Is a natural phenomenon. However human action, or inaction in some circumstances, can speed the development of resistance or make it worse. Some of the factors that contribute to the development of drug resistance are well-known and they're portrayed on this graphic. And here too, I'm only going to comment on a small number of these. I always like in class to ask my students, how many of you and I should do so now if you're not to embarrassed. How many of you on every occasion which you have taken antibiotics have taken every single pill that was given to you without exception? I don't want to make my students feel bad but they just showed that they're normal people. >> [LAUGH] >> Who would took, got sick, took antibiotics, felt better and stoped taking them earlier than they should have or who took antibiotics Got a tummy ache because of the antibiotic and decided they were going to overcome this anyway, and stopped taking their drugs. But of course, what we know is that the failure of patients to take appropriate doses of drugs, is an important contributor for human behavior to the development of drug resistance. And we also know that prescribers dispensers, and patients who have access without prescribers often use medicines inappropriately. They prescribe antibiotics when those antibiotics aren't warranted. They prescribe too short a course of antibiotics, for example. And that goes along also well with poor prescribing and dispensing practices. Very sadly, there's a substantial share of the world's drugs that are actually counterfeit. They either don't contain the active ingredient that they should, or they don't contain the right amount of the active ingredient. And the use of counterfeit drugs or drugs that should be combinations but are instead only one drug, can also contribute to the development of resistance. Another important in this issue is the inappropriate use and often very common use of antibiotics for promoting health or promoting growth in animals. And in the United States for example, not so well known to many people, a much, much, much larger volume of antibiotics is consumed by livestock than is consumed for example by people. And finally, we known that when we're dealing with relatively low income countries that have weak health systems that don't have very good laboratories that aren't able to use those labs to diagnose many illnesses correctly for example. This further feeds into the possibility of poor prescribing and provider practices that can further contribute to the development of antimicrobial resistance. In addition to that, in some of these settings, of course, there is very weak infection control that can lead to hospital-borne infections. This poor sanitation and hygiene that can spread infection, and there's weak surveillance of infections within different healthcare settings. It makes it difficult to detect diseases and can enable their spread within those settings as well. Now why should we care about these things? Why is it that emerging and reemerging infectious diseases or antimicrobial resistance is so important? Well the health, social and economic impacts are the emerging and reemerging infectious diseases vary but they can be extremely substantial, extremely large and very extensive. In recent years we've seen very few deaths from emerging and reemerging infectious diseases. Nonetheless, the costs and consequences of these diseases don't appear to be related to how many people actually die, but rather they appear to be related to people's perception of how frightening or dangerous such a disease is. As we saw, for example, in the few cases of Ebola that spread in the last couple of years beyond West Africa. Now the next graphic, I hope you'll find makes this point very well. Both about the exceptionally large economic consequences of the emerging and reemerging infectious diseases but also these consequences don't seem to have much to do with the number of people who actually died. The plague in India in 1994 is estimated to have caused the Indian economy $1.7 billion. And India was, in a sense, quarantined by the world at that time. And yet only 56 people died of the plague when it occurred. Everyone that I know of when Mad Cow Disease erupted in Europe was afraid to eat meat for fear of getting Mad Cow. And yet over and almost ten year period only 41 people died of Mad Cow disease or variant Creutzfeldt-Jakob disease. I believe it's called more scientifically and the economic consequences of that were $30 billion. And even when we think about SARS or Severe Acute Respiratory Syndrome in Asia, only 238 people died in 2003. And yet those of us who were around at the time certainly remember the extraordinary fear that people had that this would spread to places where they live and it's estimated that about $30 billion of economic losses were suffered as a result of SARS. So certainly, one very important reason why we want to be able to carry out surveillance and keep ahead of understanding when diseases are going to emerge or re-emerge, or spread is the potential they have for really severe economic consequences. Now the costs of anti-microbial resistance can also be very high. First, people might be sicker for longer than they would be from drug-susceptible forms of disease. Second, they might die at higher rates than they would from those drug-susceptible forms. In addition, the financial and economic costs of drug resistance are also very, very large. The World Health Organization has estimated, for example, that it might cost ten times more to treat a case of drug-resistant TB than a case of drug-susceptible TB. Artemisinin combination therapy is about ten times more expensive than chloroquine for treating malaria. And the costs of treating someone with the combination amoxicillin clavulanic acid is estimated to be between 25 and 60 times more expensive than treating someone with penicillin. So anti-microbial resistance, just like emerging and re-emerging infectious diseases can have enormous economic consequences. Both emerging and re-emerging infectious diseases and the anti-microbial resistance post grave threats to society as we've discussed. Yet the recent events surrounding Ebola suggest that the world is not sufficiently prepared to deal with these threats effectively. In addition, the recent appearance for example, in the United States of a bacteria that's resistant to the last line of antibiotics and the lack of investment worldwide in the development of new antibiotics has highlighted the risk of anti-microbial resistance. Against this background increasing attention has been paid in the last several years to both topics. Important global discussions are also now underway about strengthening the ability of the global community to respond to emerging and reemerging infectious diseases. Over the last decade, important policy work has also been done on antimicrobial resistance led by the Center for Global Development, the World Health Organization, a recent Lancet Commission, and a very recent an important review done in the United Kingdom. These are both topics of grave importance and I encouraged you to explore them further. However for now, let me speak very broadly to some of what can be done to prevent and address the risks of both emerging and re-emerging infectious diseases and anti-microbial resistance. The next graphics speaks to some of the measures that might be taken to address emerging and re-emerging infectious diseases. First, it's possible and desirable that countries should improve their land use planning to put less pressure on the environment. And to reduce the possible spread of the many emerging and re-emerging infectious diseases that are zoonotic in origin, that spread from animals to people. Second, it's really important in conjunction with that, for example, that the public be better educated about emerging and re-emerging infectious diseases. It's essential that countries establish and maintain better surveillance systems, and better public health laboratories for dealing with these diseases. It's also critical that information be shared across countries. So that different countries are prepared to address these diseases as they emerge or reemerge elsewhere, with the possibility of spreading to their own country. It's critical, and we certainly found this out in the case of Ebola, that countries implement the international health regulations. In the case of Ebola, we found that many countries continue to have a very limited capacity for responding to public health emergencies like, some of these emerging and re-emerging infectious diseases. It's also critical that the global community enhance its ability to respond to such diseases. And to help countries do so in effective and efficient ways as well. And in order for that to happen, the global community will also have to strengthen its ability to provide financing for such work in a timely and effective way. The next graphic speaks to some of the measures that might be taken to address anti-microbial resistance. It's very important that there continue to be studies on the economic consequences of antimicrobial resistance. So that countries and actors within them, and the global community can continue to make the case for more investment in the development of new antibiotics. And so that we might understand better the constant consequence of some other problems that arise now, with over prescribing, misuse, counterfeiting, etcetera. Second, it's really critical that there be a global surveillance system for resistance, that's more coordinated than what exists now and works better both across diseases and across countries. It's important that there be better regulation and stricter monitoring of prescribing practices for antibiotics, and this is certainly true within almost all countries. The public also needs to understand much better, not only the benefits of antibiotics, but also the risks. And the risks of encouraging the development of the anti-microbial resistance through the inappropriate prescribing practices and misuse of antibiotics. It's important that antibiotics for animal husbandry be phased out and be used only for the treatment of sick animals, rather than promote animal growth, which is so often the case now. We also need new models for research and development on antibiotics. If we want to ensure that there continued to be effective antibiotics in the future, against some of the microbial threats that we face and will face. And we need both globally and nationally, improved governance of the antibiotics as well. Both emerging and re-emerging infectious diseases, any anti-microbial resistance are being given greater prominence than earlier. By now, you should understand better than before how both are result of natural phenomenon. However, you also understand that human behavior has an important role in both emerging and reemerging infectious diseases, and anti-microbial resistance. You also have a better feel for the exceptional costs of both. In addition, you know that in many respects, individual countries and the global community have failed to put in place the measures needed to prevent the emergence of these problems as far as possible, and address them in a timely manner when they do arise. Yet, there are measures which have taken could have a valuable impact on both preventing and addressing emerging and re-emerging infectious diseases, and anti-microbial resistance. In the next session, we'll speak about HIV.
