[MUSIC] Hello everyone. My name is Hiroshi Nishiura. We move on to the second lecture which is on the Pandemics and The Health Security Response. In the first of four subjects, we handle the detailed issues of pandemics. That is followed by health security response. Health security response handles not only the response to infectious diseases, but also those- to natural disasters including the accident in the Fukushima Nuclear Plant. So we handle the pandemic for the first of four subjects. And we first have to define what actually the pandemic is. What is pandemic? The pandemic is defined by the extent of the spread of infectious diseases and its one of the epidemics. What is Epidemic? Epidemic is defined as an occurrence of infectious diseases clearly in excess of the expected level for a given time period. The expected level maybe defined subjectivity if you would like to define the epidemic in a subjective manner, but it can also be defined objective manner. If expected level is statistically defined. Outbreak is almost synonymous to epidemic, and outbreak is defined as the abnormal increase in the number of cases in a group of hosts. Usually, when we use the term outbreak rather than epidemic, We intend to represent the smaller scale of the number of infectious diseases such as clusters observed in hospitals. The pandemic is, as I told you, one of the epidemics. And a pandemic is defined as an epidemic spreading over several countries or continents affecting a large number of people. In other words, we can say that the pandemic is a global epidemic. However, we narrow down the scope of our intended meaning of the pandemic, usually it's the case that we represent the influenza pandemic, or pandemic influenza. In the human history, there were a total of four different pandemic influenza virus that have emerged in the human society and that have circulated continuously. In 1918, it is very well known that the so-called Spanish Influenza MERS and that was caused by what we called the H1N1 influenza virus. H1 represents the Hemagglutinin which exists in the surface of the influenza virus and H1 is one of the types. And H1 does not react with other types such as H2 and H3. And H1, In Spanish Influenza is known to have caused a devastating pandemic on human history. And in twentieth century, there were two other influenza pandemics that were observed. One was caused by H2 and is referred to as Asian influenza. The other is H3 influenza and that's referred to as the Hong Kong influenza. And then following the emergence of those viruses, they have mutated and evolved circulating in the human society as the seasonal influenza for the long time. And as you know, in the 21st Century, the H1-2009 influenza, or the so-called Mexican or Swine influenza, have emerged and have circulated in the human society. At the present, the H1- evolved H1N1-2009 influenza virus, as well as the H3N2 are co-circulating as seasonal influenza in the human society. And then not only the influenza but some other viruses and bacteria have caused a pandemic. And this figure shows a global distribution of emerging and re-emerging infectious diseases. Across all the continents and this ranging from bacteria, viruses, to the parasites. A number of different diseases have emerged in the human society. And when we look at the time trend and geographically extent of those diseases, there's clearly an increasing trend over time. So emerging infectious diseases have increased as a function of time in the human society. So, there's an immediate question. So we have to face the risk of a pandemic continuously. Why are we forced to face the risk of pandemic? And there is a simple answer. By looking at the mechanism of emergence in an ecological point of view.