WEBVTT 00:00:00.527 --> 00:00:06.981 (Mosquito buzzing) NOTE Paragraph 00:00:10.009 --> 00:00:13.034 (Swat) NOTE Paragraph 00:00:13.034 --> 00:00:16.017 Gotcha. NOTE Paragraph 00:00:16.017 --> 00:00:19.741 Mosquitos. I hate them. 00:00:19.741 --> 00:00:21.509 Don't you? 00:00:21.509 --> 00:00:24.600 That awful buzzing sound at night around your ears 00:00:24.600 --> 00:00:26.971 that drives you absolutely crazy? 00:00:26.971 --> 00:00:29.185 Knowing that she wants to stick a needle in your skin 00:00:29.185 --> 00:00:33.271 and suck out your blood? That's awful, right? 00:00:33.271 --> 00:00:36.652 In fact, there's only one good thing I can think of 00:00:36.652 --> 00:00:39.032 when it gets to mosquitos. 00:00:39.032 --> 00:00:41.743 When they fly into our bedroom at night, 00:00:41.743 --> 00:00:44.848 they prefer to bite my wife. NOTE Paragraph 00:00:44.848 --> 00:00:46.057 But that's fascinating, right? 00:00:46.057 --> 00:00:50.663 Why does she receive more bites than I do? 00:00:50.663 --> 00:00:54.855 And the answer is smell, the smell of her body. 00:00:54.855 --> 00:00:57.505 And since we all smell different and produce chemicals 00:00:57.505 --> 00:01:01.982 on our skin that either attract or repel mosquitos, 00:01:01.982 --> 00:01:05.414 some of us are just more attractive than others. 00:01:05.414 --> 00:01:08.644 So my wife smells nicer than I do, or I just 00:01:08.644 --> 00:01:11.430 stink more than she does. NOTE Paragraph 00:01:11.430 --> 00:01:15.011 Either way, mosquitos find us in the dark 00:01:15.011 --> 00:01:17.746 by sniffing us out. They smell us. 00:01:17.746 --> 00:01:20.456 And during my Ph.D, I wanted to know exactly 00:01:20.456 --> 00:01:23.212 what chemicals from our skin mosquitos used, 00:01:23.212 --> 00:01:26.993 African malarial mosquitos use to track us down at night. 00:01:26.993 --> 00:01:30.561 And there's a whole range of compounds that they do use. 00:01:30.561 --> 00:01:33.588 And this was not going to be an easy task. 00:01:33.588 --> 00:01:36.693 And therefore, we set up various experiments. 00:01:36.693 --> 00:01:39.561 Why did we set up these experiments? 00:01:39.561 --> 00:01:42.914 Because half the world's population runs the risk 00:01:42.914 --> 00:01:46.120 of contracting a killer disease like malaria 00:01:46.120 --> 00:01:48.822 through a simple mosquito bite. 00:01:48.822 --> 00:01:51.189 Every 30 seconds, somewhere on this planet, 00:01:51.189 --> 00:01:54.860 a child dies of malaria, and Paul Levy this morning, 00:01:54.860 --> 00:01:58.707 he was talking about the metaphor of the 727 crashing into the United States. 00:01:58.707 --> 00:02:04.288 Well, in Africa, we have the equivalent of seven jumbo 747s 00:02:04.288 --> 00:02:07.089 crashing every day. 00:02:07.089 --> 00:02:10.330 But perhaps if we can attract these mosquitos to traps, 00:02:10.330 --> 00:02:14.031 bait it with our smell, we may be able to stop transmission 00:02:14.031 --> 00:02:15.861 of disease. NOTE Paragraph 00:02:15.861 --> 00:02:18.109 Now solving this puzzle was not an easy thing, 00:02:18.109 --> 00:02:21.346 because we produce hundreds of different chemicals on the skin, 00:02:21.346 --> 00:02:23.763 but we undertook some remarkable experiments 00:02:23.763 --> 00:02:27.555 that managed us to resolve this puzzle very quickly indeed. NOTE Paragraph 00:02:27.555 --> 00:02:30.918 First, we observed that not all mosquito species 00:02:30.918 --> 00:02:34.766 bite on the same part of the body. Strange. 00:02:34.766 --> 00:02:36.385 So we set up an experiment 00:02:36.385 --> 00:02:39.997 whereby we put a naked volunteer in a large cage, 00:02:39.997 --> 00:02:43.136 and in that cage we released mosquitos 00:02:43.136 --> 00:02:46.455 to see where they were biting on the body of that person. 00:02:46.455 --> 00:02:49.054 And we found some remarkable differences. 00:02:49.054 --> 00:02:51.417 On the left here you see the bites 00:02:51.417 --> 00:02:54.342 by the Dutch malarial mosquito on this person. 00:02:54.342 --> 00:02:57.370 They had a very strong preference for biting on the face. 00:02:57.370 --> 00:02:59.832 In contrast, the African malarial mosquito 00:02:59.832 --> 00:03:05.637 had a very strong preference for biting the ankles and feet of this person, 00:03:05.637 --> 00:03:08.102 and that of course we should have known all along 00:03:08.102 --> 00:03:12.574 because they're called mosqui-toes, you see? (Laughter) 00:03:12.574 --> 00:03:15.681 That's right. (Applause) NOTE Paragraph 00:03:15.681 --> 00:03:21.334 And so we started focusing on the smell of feet, 00:03:21.334 --> 00:03:22.906 on the smell of human feet, 00:03:22.906 --> 00:03:26.608 until we came across a remarkable statement in the literature 00:03:26.608 --> 00:03:30.266 that said that cheese smells after feet 00:03:30.266 --> 00:03:34.348 rather than the reverse. Think of it. 00:03:34.348 --> 00:03:36.607 And this triggered us to do a remarkable experiment. 00:03:36.607 --> 00:03:40.986 We tried, with a tiny little piece of Limburger cheese, 00:03:40.986 --> 00:03:43.658 which smells badly after feet, 00:03:43.658 --> 00:03:46.155 to attract African malaria mosquitos. 00:03:46.155 --> 00:03:48.887 And you know what? It worked. 00:03:48.887 --> 00:03:54.222 In fact, it worked so well that now we have a synthetic mixture 00:03:54.222 --> 00:03:58.736 of the aroma of Limburger cheese that we're using in Tanzania 00:03:58.736 --> 00:04:00.848 and has been shown there to be two to three times 00:04:00.848 --> 00:04:04.730 more attractive to mosquitos than humans. 00:04:04.730 --> 00:04:08.251 Limburg, be proud of your cheese, 00:04:08.251 --> 00:04:11.448 as it is now used in the fight against malaria. 00:04:11.448 --> 00:04:18.244 (Applause) 00:04:18.244 --> 00:04:21.178 That's the cheese, just to show you. NOTE Paragraph 00:04:21.178 --> 00:04:24.357 My second story is remarkable as well. 00:04:24.357 --> 00:04:27.972 It's about man's best friend. It's about dogs. 00:04:27.972 --> 00:04:28.965 And I will show you 00:04:28.965 --> 00:04:32.102 how we can use dogs in the fight against malaria. 00:04:32.102 --> 00:04:35.770 One of the best ways of killing mosquitos 00:04:35.770 --> 00:04:38.725 is not to wait until they fly around like adults 00:04:38.725 --> 00:04:41.812 and bite people and transmit disease. 00:04:41.812 --> 00:04:45.715 It's to kill them when they're still in the water as larvae. 00:04:45.715 --> 00:04:50.440 Why? Because they are just like the CIA. 00:04:50.440 --> 00:04:54.592 In that pool of water, these larvae are concentrated. 00:04:54.592 --> 00:04:57.274 They're all together there. They are immobile. 00:04:57.274 --> 00:05:00.442 They can't escape from that water. They can't fly. 00:05:00.442 --> 00:05:03.899 And they're accessible. You can actually walk up 00:05:03.899 --> 00:05:08.158 to that pool and you can kill them there, right? NOTE Paragraph 00:05:08.158 --> 00:05:12.030 So the problem that we face with this is that, 00:05:12.030 --> 00:05:15.191 throughout the landscape, all these pools of water 00:05:15.191 --> 00:05:17.914 with the larvae, they are scattered all over the place, 00:05:17.914 --> 00:05:20.822 which makes it very hard for an inspector like this 00:05:20.822 --> 00:05:24.800 to actually find all these breeding sites and treat them with insecticides. 00:05:24.800 --> 00:05:27.331 And last year we thought very, very hard, 00:05:27.331 --> 00:05:30.706 how can we resolve this problem? Until we realized 00:05:30.706 --> 00:05:33.969 that just like us, we have a unique smell, 00:05:33.969 --> 00:05:38.480 that mosquito larvae also have a very unique smell. NOTE Paragraph 00:05:38.480 --> 00:05:40.573 And so we set up another crazy experiment, 00:05:40.573 --> 00:05:42.645 because we collected the smell of these larvae, 00:05:42.645 --> 00:05:47.011 put it on pieces of cloth, and then did something very remarkable. 00:05:47.011 --> 00:05:49.404 Here we have a bar with four holes, 00:05:49.404 --> 00:05:52.207 and we put the smell of these larvae in the left hole. 00:05:52.207 --> 00:05:53.282 Ooh, that was very quick. 00:05:53.282 --> 00:05:55.726 And then you see the dog. It's called Tweed. It's a border collie. 00:05:55.726 --> 00:05:58.641 He's examining these holes, and now he's got it already. 00:05:58.641 --> 00:06:01.138 He's going back to check the control holes again, 00:06:01.138 --> 00:06:02.621 but he's coming back to the first one, 00:06:02.621 --> 00:06:05.278 and now he's locking into that smell, 00:06:05.278 --> 00:06:07.508 which means that now we can use dogs 00:06:07.508 --> 00:06:09.836 with these inspectors to much better find 00:06:09.836 --> 00:06:12.220 the breeding sites of mosquitos in the field, 00:06:12.220 --> 00:06:15.089 and therefore have a much bigger impact on malaria. 00:06:15.089 --> 00:06:18.803 This lady is Ellen van der Zweep. She's one of the best dog-trainers in the world, 00:06:18.803 --> 00:06:21.678 and she believes that we can do a lot more. 00:06:21.678 --> 00:06:25.396 Since we also know that people that carry malaria parasites 00:06:25.396 --> 00:06:28.372 smell different compared to people that are uninfected, 00:06:28.372 --> 00:06:30.678 she's convinced that we can train dogs 00:06:30.678 --> 00:06:34.368 to find people that carry the parasite. 00:06:34.368 --> 00:06:36.551 That means that in a population where malaria 00:06:36.551 --> 00:06:40.444 has gone down all the way, and there's few people remaining with parasites, 00:06:40.444 --> 00:06:42.023 that the dogs can find these people, 00:06:42.023 --> 00:06:46.262 we can treat them with anti-malarial drugs, and give the final blow to malaria. 00:06:46.262 --> 00:06:49.770 Man's best friend in the fight against malaria. NOTE Paragraph 00:06:49.770 --> 00:06:52.808 My third story is perhaps even more remarkable, 00:06:52.808 --> 00:06:57.657 and, I should say, has never been shown to the public until today. 00:06:57.657 --> 00:06:59.727 Yeah. 00:06:59.727 --> 00:07:02.933 It's a crazy story, but I believe it's perhaps the best 00:07:02.933 --> 00:07:06.252 and ultimate revenge against mosquitos ever. 00:07:06.252 --> 00:07:09.426 In fact, people have told me that now they will enjoy 00:07:09.426 --> 00:07:12.488 being bitten by mosquitos. 00:07:12.488 --> 00:07:15.196 And the question of course is, what would make someone 00:07:15.196 --> 00:07:17.806 enjoy being bitten by mosquitos? 00:07:17.806 --> 00:07:19.066 And the answer 00:07:19.066 --> 00:07:23.183 I have right here in my pocket, 00:07:23.183 --> 00:07:25.893 if I get it. 00:07:25.893 --> 00:07:29.239 It's a tablet, a simple tablet, 00:07:29.239 --> 00:07:32.121 and when I take it with water, 00:07:32.121 --> 00:07:36.396 it does miracles. 00:07:36.396 --> 00:07:38.069 Thank you. 00:07:40.287 --> 00:07:44.029 (Drinking) NOTE Paragraph 00:07:44.029 --> 00:07:48.045 Now let me show you how this works. 00:07:48.045 --> 00:07:51.062 Here in this box I have a cage 00:07:51.062 --> 00:07:55.856 with several hundred hungry 00:07:55.856 --> 00:08:00.323 female mosquitos 00:08:00.323 --> 00:08:04.211 that I'm just about to release. (Laughter) 00:08:04.211 --> 00:08:07.331 Just kidding, just kidding. 00:08:07.331 --> 00:08:10.223 What I'm going to show you is I'm gonna stick my arm into it 00:08:10.223 --> 00:08:12.938 and I will show you how quickly they will bite. 00:08:12.938 --> 00:08:14.935 Here we go. 00:08:14.935 --> 00:08:18.357 Don't worry, I do this all the time in the lab. 00:08:18.357 --> 00:08:22.159 There we go. Okay. 00:08:22.159 --> 00:08:27.202 Now, on the video, on the video here, 00:08:27.202 --> 00:08:28.570 I'm going to show you exactly the same thing, 00:08:28.570 --> 00:08:31.329 except that what I'm showing you on the video 00:08:31.329 --> 00:08:34.895 happened one hour after I took the tablet. 00:08:34.895 --> 00:08:39.619 Have a look. That doesn't work. Okay. Sorry about that. 00:08:39.619 --> 00:08:42.018 I'm sticking in my arm, I'm giving them a big juicy 00:08:42.018 --> 00:08:44.286 blood meal, I'm shaking them off, and we follow them through time 00:08:44.286 --> 00:08:47.303 to see these mosquitos get very, very sick indeed, 00:08:47.303 --> 00:08:49.462 here shown in fast motion, 00:08:49.462 --> 00:08:52.826 and three hours later what we see at the bottom 00:08:52.826 --> 00:08:55.910 of the cage is dead mosquitos, 00:08:55.910 --> 00:09:00.241 very dead mosquitos, and I'm going to say, ladies and gentlemen, 00:09:00.241 --> 00:09:02.106 we have swapped the cards with mosquitos. 00:09:02.106 --> 00:09:06.826 They don't kill us. We kill them. 00:09:06.826 --> 00:09:14.983 (Applause) NOTE Paragraph 00:09:14.983 --> 00:09:21.067 Now — (Laughter) — 00:09:21.067 --> 00:09:22.905 Maastricht, be prepared. 00:09:22.905 --> 00:09:25.031 Now think of what we can do with this. 00:09:25.031 --> 00:09:27.229 We can actually use this to contain outbreaks 00:09:27.229 --> 00:09:30.615 of mosquito-born diseases, of epidemics, right? 00:09:30.615 --> 00:09:32.632 And better still, imagine what would happen if, 00:09:32.632 --> 00:09:35.691 in a very large area, everyone would take these drugs, 00:09:35.691 --> 00:09:37.952 this drug, for just three weeks. 00:09:37.952 --> 00:09:40.360 That would give us an opportunity to actually eliminate 00:09:40.360 --> 00:09:41.970 malaria as a disease. NOTE Paragraph 00:09:41.970 --> 00:09:46.064 So cheese, dogs and a pill to kill mosquitos. 00:09:46.064 --> 00:09:49.702 That's the kind of out-of-the-box science that I love doing, 00:09:49.702 --> 00:09:52.207 for the betterment of mankind, 00:09:52.207 --> 00:09:55.008 but especially for her, so that she can grow up 00:09:55.008 --> 00:09:59.808 in a world without malaria. Thank you. (Applause)