Welcome. Today we are going to speak about neglected tropical diseases or NTDs as they are called. By the time this session is over, you should be able to speak comfortably about the definition of a neglected tropical disease, the burden of some of the most important NTDs. Who is most affected by these diseases, the risk factors for the burden of neglected tropical diseases, and steps that can be taken to reduce the neglected tropical disease burden. Let's turn to our students for some help in understanding several key terms that relate to the NTDs. What's an NTD? >> Yes, so it's a group of parasitic and bacterial infections that are mainly prevalent in tropical and subtropical areas. >> Excellent, and who do these diseases largely affect? >> They largely affect people as said, in tropical and subtropical areas and people who often don't have good access to healthcare services as well. >> And are these usually better off people or less well off people? >> No, less well off people. >> Some people talk, in fact, about the NTDs affecting the bottom billion, the poorest billion people in the world. And then fact about one sixth of the people in the world are infected with one or more of the NTDs. And Rachael, why are these diseases called the neglected tropical diseases? >> Because until fairly recently very little attention has been paid to the NTDs especially in terms of research. >> And probably, if I might, also in terms of practice in efforts to address them so that has greatly increased in the last decade plus. Now, let's look at the burden of the neglected tropical diseases. Indeed, the World Health Organization, now classify's 17 different diseases as the Neglected Tropical Diseases. Here is the list of them and I want to encourage you with the help of the websites of the U.S. Centers for Disease Control and Prevention, the Global Network on Neglected Tropical Diseases of the World Health Organization. To explore there by going into those websites and looking up the individual diseases you'll find an interesting account of each one of them. And let's look now at the burden of some of the most prevalent of the neglected tropical diseases. And here what you see is that there's more than a billion people, more than one billion people and probably about 500 million young people are infected with one or more of the neglected tropical diseases. And here what we see is one of the NTDs itself, roundworm. Infects itself, about a billion people, we see some of the other soil transmitted infecting around 700 million people. And even here when we talk about lymphatic filariasis or elephantiasis we're still looking at a world in some where around 40 million people are infected. Now let's look for a second at the endemicity of these diseases, and the countries in which you find them. And here what we see, in this graphic, is a map that shows the different endemicity scenarios. And that is countries in which one might find five or six or seven or more of these diseases to be endemic, to be found in those countries. And if Lindsay could highlight the countries in which you see five NTDs these are the ones in green. And in yellow we'll see the countries that had six NTDs. And in blue we'll see those countries where in fact seven, or more NTD's can be found. It's really important as well to understand how widespread these diseases are, and what a large share of some populations is infected. It's been estimated for example that about 75% of the school children in Rwanda are infected with soil transmitted or the so called wormy diseases. Now there are a number of reasons why the neglected tropical diseases, have been so called you know neglected. One of them is they affect such poor people who are often kind of, forgive my saying so, out of sight and out of mind by other members in society. But two, another important one is that these diseases aren't very often associated with deaths. However, they can cause an enormous amount of illness and disability. And in fact some have suggested that if we added up the disability adjusted life years caused by the most prevalent of the neglected tropical diseases. We now end up, for example, with as many dally's as are cost annually by malaria. Now as I mentioned, these diseases tend to infect the poorest people in certain climatic zones. Women and children are living in anhygienic circumstances. And have limited access to safe water and sanitation are also more at risk. But pregnant workers, pregnant women sorry, pregnant woman, farm workers and people who work around water are also at special risk. Now the global health community has decided to focus it's attention on seven of these diseases given their prevalence and the manner in which they can be addressed. And let's look at them. These are round worm, whip worm, hook work, Schistosomiasis, Lymphatic Filariasis, Onchocerciasis, and Trachoma. Without going into too much detail, let me comment of very briefly on how these diseases are transmitted. The soil transmitted helminths are transmitted when eggs pass from the host in feces and then are transmitted when humans ingest the eggs of the worm. Schistosomiasis is transmitted when flukes infect freshwater snails. When humans come in contact with them, the Fluke can penetrate the skin. Lymphatic filariasis which is often refered to as elephantiasis. This disease that causes substantial swelling and sometimes horrible swelling of the extremities. Is spread when mosquitoes bite an infected person, ingest the larvae and pass it on to another person. Onchocerciasis is spread in a similar way, but by black flies. And Trachoma, which is a blinding disease caused by a bacteria, is transmitted when someone comes in contact with discharge from the eye, or when flies do the same thing and then land on another persons eye. As I've mentioned already the neglected tropical diseases or NTDs can have debilitating health, social and economic consequences. And this graphic for example, speaks just to some of the health impacts of these few neglected tropical diseases. And here, I think the one with which people might be most familiar again is Lymphatic Filariasis. They can cause exceptional swelling of not just the limbs but also the genitals. But we also see trachoma which can be addressed as we'll talk about with a very simple drug regiment and yet causes blindness, and corneal scarring. And, here, we see some of the other health manifestations of these diseases, again, often in ways that are disfiguring, or disabling, and cause a substantial loss of healthy life years. Now, in addition because of some of these disabilities that these produce, or the disfigurement that they can produce, it wouldn't be a surprise to you to note how stigmatizing some of these diseases can be, as well. And economic consequences of the NTDs are also very high, soil-transmitted the wormy diseases, can affect child growth. Attendance at and performance in school. Regions severely affected by Onchocerciasis had large numbers of blind people and a substantial part of their land area that they couldn't even farm for example because of the risks of getting Oncho and becoming blind. It's been estimated that Trachoma alone which affects relatively fewer people than many of the other NTDs, causes almost a three billion dollar a year loss in productivity. Now some very important progress has been made against a number of the neglected tropical diseases, including the seven we've been discussing. In addition, Guinea worm is on the verge of being eradicated and would be, if it gets there before Polio, only the second disease found in humans to ever be eradicated. Let's talk now about some of the basic approaches to how neglected tropical diseases are addressed. Before turning to one of the leading authorities in the world on NTDs for further comments on that topic. One of the basic principles of addressing NTDs has been mass drug administration. This is an approach in which drugs are given to people living in endemic areas usually several times a year. To prevent they're getting infected with the targeted NTDs. This is generally done in a community based in directed manner. The idea is that mass drug administration over time, sometimes 10 to 20 years, will completely stop transmission of a disease. Another principle is to provide treatment on the basis of a map of the diseases that are endemic to an area. Earlier, different NTDs were usually targeted through separate programs. The idea now is to address NTDs through a coordinated rapid impact package, in this case, drugs are given out in a coordinated program at the community level depending on the disease burden in a particular place. And let's look at a graphic of this so called endemicity scenarios. So let's imagine for example Uganda and the districts of the Uganda. And let's think of having mapped the different NTDs that are prevalent in different districts in that country. And here what we see is we mapped them according to a number of different scenarios. If, for example, the district should only have soil transmitted helminths, these drugs, albendazole and mebendazole, would be given. If, for example, this is a district that has soil transmitted helminths, lymphatic filariasis, and schistosomiasis, the appropriate drugs for that would be given. And if, unfortunately, it were a district that had soil transmitted helminths, lymphatic filariases, schistosomiasis, and onchocerciasis, then another package of drugs would be provided to the people in those communities. A third important point to note is, that the efforts to address neglected tropical diseases. Have been based on important partnerships between countries, their global development partners and pharmaceutical companies. This is an interesting, important and cost saving model that has helped to enable the rapid impact package to be delivered for about 50 US cents per person per year. For insightful comments about how neglected tropical diseases can be addressed and the challenges of doing so, I'd like to turn to my friend Dr Peter Hotez. Dr Hotez is the dean at the School of Tropical Medicine at Baylor University. And among other things, he's one of the leading authorities in the world, on Neglected Tropical Diseases. And I must say that Dr. Hotez is also been a pioneer and work on NTDs and is one of the people who in fact caused the NTDs to be much less neglected than they were before. Dr. Hotez