WEBVTT 00:00:00.800 --> 00:00:04.440 (Mosquito buzzing) NOTE Paragraph 00:00:10.040 --> 00:00:11.240 (Swat) NOTE Paragraph 00:00:13.480 --> 00:00:14.630 Gotcha. 00:00:15.960 --> 00:00:17.160 Mosquitos. 00:00:17.880 --> 00:00:19.080 I hate them. 00:00:20.120 --> 00:00:21.320 Don't you? 00:00:21.960 --> 00:00:24.576 That awful buzzing sound at night around your ears 00:00:24.600 --> 00:00:26.200 that drives you absolutely crazy? 00:00:27.280 --> 00:00:29.776 Knowing that she wants to stick a needle in your skin 00:00:29.800 --> 00:00:31.000 and suck out your blood? 00:00:31.520 --> 00:00:32.720 That's awful, right? 00:00:33.280 --> 00:00:37.840 In fact, there's only one good thing I can think of when it gets to mosquitos. 00:00:39.000 --> 00:00:40.920 When they fly into our bedroom at night, 00:00:41.800 --> 00:00:43.134 they prefer to bite my wife. NOTE Paragraph 00:00:44.840 --> 00:00:46.296 But that's fascinating, right? 00:00:46.320 --> 00:00:49.760 Why does she receive more bites than I do? 00:00:50.600 --> 00:00:53.016 And the answer is smell, 00:00:53.040 --> 00:00:54.240 the smell of her body. 00:00:55.120 --> 00:00:58.976 And since we all smell different and produce chemicals on our skin 00:00:59.000 --> 00:01:01.936 that either attract or repel mosquitos, 00:01:01.960 --> 00:01:04.640 some of us are just more attractive than others. 00:01:05.360 --> 00:01:10.600 So my wife smells nicer than I do, or I just stink more than she does. NOTE Paragraph 00:01:11.560 --> 00:01:17.776 Either way, mosquitos find us in the dark by sniffing us out. They smell us. 00:01:17.800 --> 00:01:21.096 And during my PhD, I wanted to know exactly 00:01:21.120 --> 00:01:23.176 what chemicals from our skin mosquitos use, 00:01:23.200 --> 00:01:26.440 African malaria mosquitos use to track us down at night. 00:01:27.680 --> 00:01:30.320 And there's a whole range of compounds that they do use. 00:01:30.760 --> 00:01:32.800 And this was not going to be an easy task. 00:01:33.600 --> 00:01:36.640 And therefore we set up various experiments. 00:01:37.640 --> 00:01:39.816 Why did we set up these experiments? 00:01:39.840 --> 00:01:42.136 Because half the world's population 00:01:42.160 --> 00:01:46.456 runs the risk of contracting a killer disease like malaria 00:01:46.480 --> 00:01:48.040 through a simple mosquito bite. 00:01:48.840 --> 00:01:51.256 Every 30 seconds, somewhere on this planet, 00:01:51.280 --> 00:01:53.736 a child dies of malaria, 00:01:53.760 --> 00:01:56.656 and Paul Levy this morning, he was talking about the metaphor 00:01:56.680 --> 00:01:59.176 of the 727 crashing into the United States. 00:01:59.200 --> 00:02:04.856 Well, in Africa, we have the equivalent of seven jumbo 747s 00:02:04.880 --> 00:02:06.160 crashing every day. 00:02:07.320 --> 00:02:10.616 But perhaps if we can attract these mosquitos to traps, 00:02:10.639 --> 00:02:12.216 bait it with our smell, 00:02:12.240 --> 00:02:15.160 we may be able to stop transmission of disease. NOTE Paragraph 00:02:16.360 --> 00:02:18.576 Now, solving this puzzle was not an easy thing, 00:02:18.600 --> 00:02:21.576 because we produce hundreds of different chemicals on the skin, 00:02:21.600 --> 00:02:24.256 but we undertook some remarkable experiments 00:02:24.280 --> 00:02:27.576 that managed us to resolve this puzzle very quickly indeed. NOTE Paragraph 00:02:27.600 --> 00:02:30.936 First, we observed that not all mosquito species 00:02:30.960 --> 00:02:32.880 bite on the same part of the body. 00:02:33.600 --> 00:02:34.816 Strange. 00:02:34.840 --> 00:02:36.416 So we set up an experiment 00:02:36.440 --> 00:02:39.800 whereby we put a naked volunteer in a large cage, 00:02:40.760 --> 00:02:43.296 and in that cage we released mosquitos 00:02:43.320 --> 00:02:46.000 to see where they were biting on the body of that person. 00:02:46.600 --> 00:02:48.560 And we found some remarkable differences. 00:02:49.000 --> 00:02:51.440 On the left here you see the bites 00:02:52.040 --> 00:02:54.296 by the Dutch malaria mosquito on this person. 00:02:54.320 --> 00:02:57.000 They had a very strong preference for biting on the face. 00:02:57.840 --> 00:03:00.336 In contrast, the African malaria mosquito 00:03:00.360 --> 00:03:05.536 had a very strong preference for biting the ankles and feet of this person. 00:03:05.560 --> 00:03:08.016 And that of course we should have known all along 00:03:08.040 --> 00:03:11.176 because they're called mosqui-toes, you see? NOTE Paragraph 00:03:11.200 --> 00:03:12.536 (Laughter) NOTE Paragraph 00:03:12.560 --> 00:03:13.776 That's right. NOTE Paragraph 00:03:13.800 --> 00:03:16.056 (Applause) NOTE Paragraph 00:03:16.080 --> 00:03:20.440 And so we started focusing on the smell of feet, 00:03:21.240 --> 00:03:23.056 on the smell of human feet, 00:03:23.080 --> 00:03:26.120 until we came across a remarkable statement in the literature 00:03:26.840 --> 00:03:30.000 that said that cheese smells after feet 00:03:30.640 --> 00:03:32.240 rather than the reverse. 00:03:32.840 --> 00:03:34.296 Think of it. 00:03:34.320 --> 00:03:36.749 And this triggered us to do a remarkable experiment. 00:03:36.773 --> 00:03:41.816 We tried, with a tiny little piece of Limburger cheese, 00:03:41.840 --> 00:03:43.600 which smells badly after feet, 00:03:44.240 --> 00:03:46.376 to attract African malaria mosquitos. 00:03:46.400 --> 00:03:48.280 And you know what? It worked. 00:03:49.440 --> 00:03:52.416 In fact, it worked so well 00:03:52.440 --> 00:03:56.976 that now we have a synthetic mixture of the aroma of Limburger cheese 00:03:57.000 --> 00:03:58.776 that we're using in Tanzania 00:03:58.800 --> 00:04:00.016 and has been shown there 00:04:00.040 --> 00:04:04.000 to be two to three times more attractive to mosquitos than humans. 00:04:04.760 --> 00:04:08.256 Limburg, be proud of your cheese, 00:04:08.280 --> 00:04:11.416 as it is now used in the fight against malaria. NOTE Paragraph 00:04:11.440 --> 00:04:14.360 (Applause) NOTE Paragraph 00:04:18.279 --> 00:04:20.399 That's the cheese, just to show you. NOTE Paragraph 00:04:21.399 --> 00:04:23.880 My second story is remarkable as well. 00:04:24.720 --> 00:04:27.080 It's about man's best friend. It's about dogs. 00:04:27.960 --> 00:04:31.320 And I will show you how we can use dogs in the fight against malaria. 00:04:32.880 --> 00:04:35.736 One of the best ways of killing mosquitos 00:04:35.760 --> 00:04:39.056 is not to wait until they fly around like adults 00:04:39.080 --> 00:04:40.960 and bite people and transmit disease. 00:04:41.800 --> 00:04:45.200 It's to kill them when they're still in the water as larvae. 00:04:45.920 --> 00:04:47.136 Why? 00:04:47.160 --> 00:04:49.520 Because they are just like the CIA. 00:04:50.480 --> 00:04:54.456 In that pool of water, these larvae are concentrated. 00:04:54.480 --> 00:04:57.136 They're all together there. They are immobile. 00:04:57.160 --> 00:04:58.816 They can't escape from that water. 00:04:58.840 --> 00:05:00.416 They can't fly. 00:05:00.440 --> 00:05:03.136 And they're accessible. 00:05:03.160 --> 00:05:07.200 You can actually walk up to that pool and you can kill them there, right? NOTE Paragraph 00:05:08.120 --> 00:05:11.736 So the problem that we face with this 00:05:11.760 --> 00:05:15.656 is that, throughout the landscape, all these pools of water with the larvae, 00:05:15.680 --> 00:05:17.656 they are scattered all over the place, 00:05:17.680 --> 00:05:20.896 which makes it very hard for an inspector like this 00:05:20.920 --> 00:05:24.480 to actually find all these breeding sites and treat them with insecticides. 00:05:25.040 --> 00:05:29.240 And last year we thought very, very hard, how can we resolve this problem? 00:05:29.960 --> 00:05:34.416 Until we realized that just like us -- we have a unique smell -- 00:05:34.440 --> 00:05:37.720 mosquito larvae also have a very unique smell. NOTE Paragraph 00:05:38.480 --> 00:05:40.656 And so we set up another crazy experiment, 00:05:40.680 --> 00:05:43.016 because we collected the smell of these larvae, 00:05:43.040 --> 00:05:46.320 put it on pieces of cloth, and then did something very remarkable. 00:05:46.960 --> 00:05:49.376 Here we have a bar with four holes 00:05:49.400 --> 00:05:52.176 and we put the smell of these larvae in the left hole. 00:05:52.200 --> 00:05:53.416 Oh, that was very quick. 00:05:53.440 --> 00:05:56.576 And then you see the dog. It's called Tweed. It's a border collie. 00:05:56.600 --> 00:05:59.216 He's examining these holes and now he's got it already. 00:05:59.240 --> 00:06:01.576 He's going back to check the control holes again, 00:06:01.600 --> 00:06:03.456 but he's coming back to the first one, 00:06:03.480 --> 00:06:05.296 and now he's locking into that smell, 00:06:05.320 --> 00:06:08.936 which means that now we can use dogs with these inspectors 00:06:08.960 --> 00:06:12.176 to much better find the breeding sites of mosquitos in the field, 00:06:12.200 --> 00:06:14.600 and therefore have a much bigger impact on malaria. 00:06:15.320 --> 00:06:16.936 This lady is Ellen van der Zweep. 00:06:16.960 --> 00:06:19.176 She's one of the best dog trainers in the world 00:06:19.200 --> 00:06:21.240 and she believes that we can do a lot more. 00:06:22.160 --> 00:06:25.616 Since we also know that people that carry malaria parasites 00:06:25.640 --> 00:06:28.496 smell different compared to people that are uninfected, 00:06:28.520 --> 00:06:32.920 she's convinced that we can train dogs to find people that carry the parasite. 00:06:34.800 --> 00:06:38.216 That means that in a population where malaria has gone down all the way 00:06:38.240 --> 00:06:40.656 and there's few people remaining with parasites, 00:06:40.680 --> 00:06:42.416 that the dogs can find these people, 00:06:42.440 --> 00:06:46.336 we can treat them with antimalarial drugs and give the final blow to malaria. 00:06:46.360 --> 00:06:48.640 Man's best friend in the fight against malaria. NOTE Paragraph 00:06:50.080 --> 00:06:52.320 My third story is perhaps even more remarkable 00:06:53.280 --> 00:06:56.760 and, I should say, has never been shown to the public until today. 00:06:57.800 --> 00:06:59.000 Yeah. 00:06:59.760 --> 00:07:04.736 It's a crazy story, but I believe it's perhaps the best and ultimate revenge 00:07:04.760 --> 00:07:05.960 against mosquitos ever. 00:07:06.440 --> 00:07:07.936 In fact, people have told me 00:07:07.960 --> 00:07:11.440 that now they will enjoy being bitten by mosquitos. 00:07:12.520 --> 00:07:14.056 And the question of course is, 00:07:14.080 --> 00:07:17.240 what would make someone enjoy being bitten by mosquitos? 00:07:17.800 --> 00:07:20.120 And the answer I have right here 00:07:21.080 --> 00:07:22.280 in my pocket, 00:07:23.440 --> 00:07:24.640 if I get it. 00:07:25.960 --> 00:07:27.160 It's a tablet, 00:07:28.000 --> 00:07:29.216 a simple tablet, 00:07:29.240 --> 00:07:31.600 and when I take it with water, 00:07:32.480 --> 00:07:34.080 it does miracles. 00:07:36.960 --> 00:07:38.240 Thank you. NOTE Paragraph 00:07:44.360 --> 00:07:47.280 Now, let me show you how this works. 00:07:47.960 --> 00:07:50.680 Here in this box I have a cage 00:07:51.920 --> 00:07:53.120 with several hundred 00:07:54.000 --> 00:07:58.960 hungry female mosquitos 00:08:00.320 --> 00:08:02.776 that I'm just about to release. NOTE Paragraph 00:08:02.800 --> 00:08:04.576 (Laughter) NOTE Paragraph 00:08:04.600 --> 00:08:05.920 Just kidding, just kidding. 00:08:07.360 --> 00:08:10.416 What I'm going to show you is I'm gonna stick my arm into it 00:08:10.440 --> 00:08:12.720 and I will show you how quickly they will bite. 00:08:13.480 --> 00:08:14.680 Here we go. 00:08:15.480 --> 00:08:17.671 Don't worry, I do this all the time in the lab. 00:08:18.320 --> 00:08:19.520 There we go. 00:08:20.560 --> 00:08:21.760 OK. 00:08:22.240 --> 00:08:24.240 Now, on the video, 00:08:25.320 --> 00:08:26.680 on the video here, 00:08:27.160 --> 00:08:29.296 I'm going to show you exactly the same thing, 00:08:29.320 --> 00:08:31.456 except that what I'm showing you on the video 00:08:31.480 --> 00:08:34.280 happened one hour after I took the tablet. 00:08:34.799 --> 00:08:36.000 Have a look. 00:08:36.720 --> 00:08:37.936 That doesn't work. 00:08:37.960 --> 00:08:39.159 OK. Sorry about that. 00:08:39.600 --> 00:08:42.576 I'm sticking in my arm, I'm giving them a big juicy blood meal, 00:08:42.600 --> 00:08:45.096 I'm shaking them off, and we follow them through time 00:08:45.120 --> 00:08:47.616 to see these mosquitos get very, very sick indeed, 00:08:47.640 --> 00:08:49.160 here shown in fast motion. 00:08:49.920 --> 00:08:53.856 And three hours later what we see at the bottom of the cage 00:08:53.880 --> 00:08:55.080 is dead mosquitos, 00:08:56.000 --> 00:08:57.960 very dead mosquitos. 00:08:58.800 --> 00:09:00.816 And I'm going to say, ladies and gentlemen, 00:09:00.840 --> 00:09:02.793 we have swapped the cards with mosquitos. 00:09:02.817 --> 00:09:06.416 They don't kill us. We kill them. NOTE Paragraph 00:09:06.440 --> 00:09:08.640 (Applause) NOTE Paragraph 00:09:15.640 --> 00:09:16.840 Now -- NOTE Paragraph 00:09:17.960 --> 00:09:20.160 (Laughter) 00:09:21.160 --> 00:09:22.680 Maastricht, be prepared. 00:09:23.400 --> 00:09:25.296 Now, think of what we can do with this. 00:09:25.320 --> 00:09:27.456 We can actually use this to contain outbreaks 00:09:27.480 --> 00:09:30.560 of mosquito-born diseases, of epidemics, right? 00:09:31.160 --> 00:09:33.176 And better still, imagine what would happen 00:09:33.200 --> 00:09:37.400 if, in a very large area, everyone would take these drugs, for just three weeks. 00:09:37.920 --> 00:09:39.536 That would give us an opportunity 00:09:39.560 --> 00:09:41.680 to actually eliminate malaria as a disease. NOTE Paragraph 00:09:42.360 --> 00:09:46.296 So cheese, dogs and a pill to kill mosquitos. 00:09:46.320 --> 00:09:49.280 That's the kind of out-of-the-box science that I love doing, 00:09:50.160 --> 00:09:52.136 for the betterment of mankind, 00:09:52.160 --> 00:09:53.776 but especially for her, 00:09:53.800 --> 00:09:57.696 so that she can grow up in a world without malaria. NOTE Paragraph 00:09:57.720 --> 00:09:58.936 Thank you. NOTE Paragraph 00:09:58.960 --> 00:10:00.240 (Applause)