1 00:00:00,800 --> 00:00:04,440 (Mosquito buzzing) 2 00:00:10,040 --> 00:00:11,240 (Swat) 3 00:00:13,480 --> 00:00:14,630 Gotcha. 4 00:00:15,960 --> 00:00:17,160 Mosquitos. 5 00:00:17,880 --> 00:00:19,080 I hate them. 6 00:00:20,120 --> 00:00:21,320 Don't you? 7 00:00:21,960 --> 00:00:24,576 That awful buzzing sound at night around your ears 8 00:00:24,600 --> 00:00:26,200 that drives you absolutely crazy? 9 00:00:27,280 --> 00:00:29,776 Knowing that she wants to stick a needle in your skin 10 00:00:29,800 --> 00:00:31,000 and suck out your blood? 11 00:00:31,520 --> 00:00:32,720 That's awful, right? 12 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. 13 00:00:39,000 --> 00:00:40,920 When they fly into our bedroom at night, 14 00:00:41,800 --> 00:00:43,134 they prefer to bite my wife. 15 00:00:44,840 --> 00:00:46,296 But that's fascinating, right? 16 00:00:46,320 --> 00:00:49,760 Why does she receive more bites than I do? 17 00:00:50,600 --> 00:00:53,016 And the answer is smell, 18 00:00:53,040 --> 00:00:54,240 the smell of her body. 19 00:00:55,120 --> 00:00:58,976 And since we all smell different and produce chemicals on our skin 20 00:00:59,000 --> 00:01:01,936 that either attract or repel mosquitos, 21 00:01:01,960 --> 00:01:04,640 some of us are just more attractive than others. 22 00:01:05,360 --> 00:01:10,600 So my wife smells nicer than I do, or I just stink more than she does. 23 00:01:11,560 --> 00:01:17,776 Either way, mosquitos find us in the dark by sniffing us out. They smell us. 24 00:01:17,800 --> 00:01:21,096 And during my PhD, I wanted to know exactly 25 00:01:21,120 --> 00:01:23,176 what chemicals from our skin mosquitos use, 26 00:01:23,200 --> 00:01:26,440 African malaria mosquitos use to track us down at night. 27 00:01:27,680 --> 00:01:30,320 And there's a whole range of compounds that they do use. 28 00:01:30,760 --> 00:01:32,800 And this was not going to be an easy task. 29 00:01:33,600 --> 00:01:36,640 And therefore we set up various experiments. 30 00:01:37,640 --> 00:01:39,816 Why did we set up these experiments? 31 00:01:39,840 --> 00:01:42,136 Because half the world's population 32 00:01:42,160 --> 00:01:46,456 runs the risk of contracting a killer disease like malaria 33 00:01:46,480 --> 00:01:48,040 through a simple mosquito bite. 34 00:01:48,840 --> 00:01:51,256 Every 30 seconds, somewhere on this planet, 35 00:01:51,280 --> 00:01:53,736 a child dies of malaria, 36 00:01:53,760 --> 00:01:56,656 and Paul Levy this morning, he was talking about the metaphor 37 00:01:56,680 --> 00:01:59,176 of the 727 crashing into the United States. 38 00:01:59,200 --> 00:02:04,856 Well, in Africa, we have the equivalent of seven jumbo 747s 39 00:02:04,880 --> 00:02:06,160 crashing every day. 40 00:02:07,320 --> 00:02:10,616 But perhaps if we can attract these mosquitos to traps, 41 00:02:10,639 --> 00:02:12,216 bait it with our smell, 42 00:02:12,240 --> 00:02:15,160 we may be able to stop transmission of disease. 43 00:02:16,360 --> 00:02:18,576 Now, solving this puzzle was not an easy thing, 44 00:02:18,600 --> 00:02:21,576 because we produce hundreds of different chemicals on the skin, 45 00:02:21,600 --> 00:02:24,256 but we undertook some remarkable experiments 46 00:02:24,280 --> 00:02:27,576 that managed us to resolve this puzzle very quickly indeed. 47 00:02:27,600 --> 00:02:30,936 First, we observed that not all mosquito species 48 00:02:30,960 --> 00:02:32,880 bite on the same part of the body. 49 00:02:33,600 --> 00:02:34,816 Strange. 50 00:02:34,840 --> 00:02:36,416 So we set up an experiment 51 00:02:36,440 --> 00:02:39,800 whereby we put a naked volunteer in a large cage, 52 00:02:40,760 --> 00:02:43,296 and in that cage we released mosquitos 53 00:02:43,320 --> 00:02:46,000 to see where they were biting on the body of that person. 54 00:02:46,600 --> 00:02:48,560 And we found some remarkable differences. 55 00:02:49,000 --> 00:02:51,440 On the left here you see the bites 56 00:02:52,040 --> 00:02:54,296 by the Dutch malaria mosquito on this person. 57 00:02:54,320 --> 00:02:57,000 They had a very strong preference for biting on the face. 58 00:02:57,840 --> 00:03:00,336 In contrast, the African malaria mosquito 59 00:03:00,360 --> 00:03:05,536 had a very strong preference for biting the ankles and feet of this person. 60 00:03:05,560 --> 00:03:08,016 And that of course we should have known all along 61 00:03:08,040 --> 00:03:11,176 because they're called mosqui-toes, you see? 62 00:03:11,200 --> 00:03:12,536 (Laughter) 63 00:03:12,560 --> 00:03:13,776 That's right. 64 00:03:13,800 --> 00:03:16,056 (Applause) 65 00:03:16,080 --> 00:03:20,440 And so we started focusing on the smell of feet, 66 00:03:21,240 --> 00:03:23,056 on the smell of human feet, 67 00:03:23,080 --> 00:03:26,120 until we came across a remarkable statement in the literature 68 00:03:26,840 --> 00:03:30,000 that said that cheese smells after feet 69 00:03:30,640 --> 00:03:32,240 rather than the reverse. 70 00:03:32,840 --> 00:03:34,296 Think of it. 71 00:03:34,320 --> 00:03:36,749 And this triggered us to do a remarkable experiment. 72 00:03:36,773 --> 00:03:41,816 We tried, with a tiny little piece of Limburger cheese, 73 00:03:41,840 --> 00:03:43,600 which smells badly after feet, 74 00:03:44,240 --> 00:03:46,376 to attract African malaria mosquitos. 75 00:03:46,400 --> 00:03:48,280 And you know what? It worked. 76 00:03:49,440 --> 00:03:52,416 In fact, it worked so well 77 00:03:52,440 --> 00:03:56,976 that now we have a synthetic mixture of the aroma of Limburger cheese 78 00:03:57,000 --> 00:03:58,776 that we're using in Tanzania 79 00:03:58,800 --> 00:04:00,016 and has been shown there 80 00:04:00,040 --> 00:04:04,000 to be two to three times more attractive to mosquitos than humans. 81 00:04:04,760 --> 00:04:08,256 Limburg, be proud of your cheese, 82 00:04:08,280 --> 00:04:11,416 as it is now used in the fight against malaria. 83 00:04:11,440 --> 00:04:14,360 (Applause) 84 00:04:18,279 --> 00:04:20,399 That's the cheese, just to show you. 85 00:04:21,399 --> 00:04:23,880 My second story is remarkable as well. 86 00:04:24,720 --> 00:04:27,080 It's about man's best friend. It's about dogs. 87 00:04:27,960 --> 00:04:31,320 And I will show you how we can use dogs in the fight against malaria. 88 00:04:32,880 --> 00:04:35,736 One of the best ways of killing mosquitos 89 00:04:35,760 --> 00:04:39,056 is not to wait until they fly around like adults 90 00:04:39,080 --> 00:04:40,960 and bite people and transmit disease. 91 00:04:41,800 --> 00:04:45,200 It's to kill them when they're still in the water as larvae. 92 00:04:45,920 --> 00:04:47,136 Why? 93 00:04:47,160 --> 00:04:49,520 Because they are just like the CIA. 94 00:04:50,480 --> 00:04:54,456 In that pool of water, these larvae are concentrated. 95 00:04:54,480 --> 00:04:57,136 They're all together there. They are immobile. 96 00:04:57,160 --> 00:04:58,816 They can't escape from that water. 97 00:04:58,840 --> 00:05:00,416 They can't fly. 98 00:05:00,440 --> 00:05:03,136 And they're accessible. 99 00:05:03,160 --> 00:05:07,200 You can actually walk up to that pool and you can kill them there, right? 100 00:05:08,120 --> 00:05:11,736 So the problem that we face with this 101 00:05:11,760 --> 00:05:15,656 is that, throughout the landscape, all these pools of water with the larvae, 102 00:05:15,680 --> 00:05:17,656 they are scattered all over the place, 103 00:05:17,680 --> 00:05:20,896 which makes it very hard for an inspector like this 104 00:05:20,920 --> 00:05:24,480 to actually find all these breeding sites and treat them with insecticides. 105 00:05:25,040 --> 00:05:29,240 And last year we thought very, very hard, how can we resolve this problem? 106 00:05:29,960 --> 00:05:34,416 Until we realized that just like us -- we have a unique smell -- 107 00:05:34,440 --> 00:05:37,720 mosquito larvae also have a very unique smell. 108 00:05:38,480 --> 00:05:40,656 And so we set up another crazy experiment, 109 00:05:40,680 --> 00:05:43,016 because we collected the smell of these larvae, 110 00:05:43,040 --> 00:05:46,320 put it on pieces of cloth, and then did something very remarkable. 111 00:05:46,960 --> 00:05:49,376 Here we have a bar with four holes 112 00:05:49,400 --> 00:05:52,176 and we put the smell of these larvae in the left hole. 113 00:05:52,200 --> 00:05:53,416 Oh, that was very quick. 114 00:05:53,440 --> 00:05:56,576 And then you see the dog. It's called Tweed. It's a border collie. 115 00:05:56,600 --> 00:05:59,216 He's examining these holes and now he's got it already. 116 00:05:59,240 --> 00:06:01,576 He's going back to check the control holes again, 117 00:06:01,600 --> 00:06:03,456 but he's coming back to the first one, 118 00:06:03,480 --> 00:06:05,296 and now he's locking into that smell, 119 00:06:05,320 --> 00:06:08,936 which means that now we can use dogs with these inspectors 120 00:06:08,960 --> 00:06:12,176 to much better find the breeding sites of mosquitos in the field, 121 00:06:12,200 --> 00:06:14,600 and therefore have a much bigger impact on malaria. 122 00:06:15,320 --> 00:06:16,936 This lady is Ellen van der Zweep. 123 00:06:16,960 --> 00:06:19,176 She's one of the best dog trainers in the world 124 00:06:19,200 --> 00:06:21,240 and she believes that we can do a lot more. 125 00:06:22,160 --> 00:06:25,616 Since we also know that people that carry malaria parasites 126 00:06:25,640 --> 00:06:28,496 smell different compared to people that are uninfected, 127 00:06:28,520 --> 00:06:32,920 she's convinced that we can train dogs to find people that carry the parasite. 128 00:06:34,800 --> 00:06:38,216 That means that in a population where malaria has gone down all the way 129 00:06:38,240 --> 00:06:40,656 and there's few people remaining with parasites, 130 00:06:40,680 --> 00:06:42,416 that the dogs can find these people, 131 00:06:42,440 --> 00:06:46,336 we can treat them with antimalarial drugs and give the final blow to malaria. 132 00:06:46,360 --> 00:06:48,640 Man's best friend in the fight against malaria. 133 00:06:50,080 --> 00:06:52,320 My third story is perhaps even more remarkable 134 00:06:53,280 --> 00:06:56,760 and, I should say, has never been shown to the public until today. 135 00:06:57,800 --> 00:06:59,000 Yeah. 136 00:06:59,760 --> 00:07:04,736 It's a crazy story, but I believe it's perhaps the best and ultimate revenge 137 00:07:04,760 --> 00:07:05,960 against mosquitos ever. 138 00:07:06,440 --> 00:07:07,936 In fact, people have told me 139 00:07:07,960 --> 00:07:11,440 that now they will enjoy being bitten by mosquitos. 140 00:07:12,520 --> 00:07:14,056 And the question of course is, 141 00:07:14,080 --> 00:07:17,240 what would make someone enjoy being bitten by mosquitos? 142 00:07:17,800 --> 00:07:20,120 And the answer I have right here 143 00:07:21,080 --> 00:07:22,280 in my pocket, 144 00:07:23,440 --> 00:07:24,640 if I get it. 145 00:07:25,960 --> 00:07:27,160 It's a tablet, 146 00:07:28,000 --> 00:07:29,216 a simple tablet, 147 00:07:29,240 --> 00:07:31,600 and when I take it with water, 148 00:07:32,480 --> 00:07:34,080 it does miracles. 149 00:07:36,960 --> 00:07:38,240 Thank you. 150 00:07:44,360 --> 00:07:47,280 Now, let me show you how this works. 151 00:07:47,960 --> 00:07:50,680 Here in this box I have a cage 152 00:07:51,920 --> 00:07:53,120 with several hundred 153 00:07:54,000 --> 00:07:58,960 hungry female mosquitos 154 00:08:00,320 --> 00:08:02,776 that I'm just about to release. 155 00:08:02,800 --> 00:08:04,576 (Laughter) 156 00:08:04,600 --> 00:08:05,920 Just kidding, just kidding. 157 00:08:07,360 --> 00:08:10,416 What I'm going to show you is I'm gonna stick my arm into it 158 00:08:10,440 --> 00:08:12,720 and I will show you how quickly they will bite. 159 00:08:13,480 --> 00:08:14,680 Here we go. 160 00:08:15,480 --> 00:08:17,671 Don't worry, I do this all the time in the lab. 161 00:08:18,320 --> 00:08:19,520 There we go. 162 00:08:20,560 --> 00:08:21,760 OK. 163 00:08:22,240 --> 00:08:24,240 Now, on the video, 164 00:08:25,320 --> 00:08:26,680 on the video here, 165 00:08:27,160 --> 00:08:29,296 I'm going to show you exactly the same thing, 166 00:08:29,320 --> 00:08:31,456 except that what I'm showing you on the video 167 00:08:31,480 --> 00:08:34,280 happened one hour after I took the tablet. 168 00:08:34,799 --> 00:08:36,000 Have a look. 169 00:08:36,720 --> 00:08:37,936 That doesn't work. 170 00:08:37,960 --> 00:08:39,159 OK. Sorry about that. 171 00:08:39,600 --> 00:08:42,576 I'm sticking in my arm, I'm giving them a big juicy blood meal, 172 00:08:42,600 --> 00:08:45,096 I'm shaking them off, and we follow them through time 173 00:08:45,120 --> 00:08:47,616 to see these mosquitos get very, very sick indeed, 174 00:08:47,640 --> 00:08:49,160 here shown in fast motion. 175 00:08:49,920 --> 00:08:53,856 And three hours later what we see at the bottom of the cage 176 00:08:53,880 --> 00:08:55,080 is dead mosquitos, 177 00:08:56,000 --> 00:08:57,960 very dead mosquitos. 178 00:08:58,800 --> 00:09:00,816 And I'm going to say, ladies and gentlemen, 179 00:09:00,840 --> 00:09:02,793 we have swapped the cards with mosquitos. 180 00:09:02,817 --> 00:09:06,416 They don't kill us. We kill them. 181 00:09:06,440 --> 00:09:08,640 (Applause) 182 00:09:15,640 --> 00:09:16,840 Now -- 183 00:09:17,960 --> 00:09:20,160 (Laughter) 184 00:09:21,160 --> 00:09:22,680 Maastricht, be prepared. 185 00:09:23,400 --> 00:09:25,296 Now, think of what we can do with this. 186 00:09:25,320 --> 00:09:27,456 We can actually use this to contain outbreaks 187 00:09:27,480 --> 00:09:30,560 of mosquito-born diseases, of epidemics, right? 188 00:09:31,160 --> 00:09:33,176 And better still, imagine what would happen 189 00:09:33,200 --> 00:09:37,400 if, in a very large area, everyone would take these drugs, for just three weeks. 190 00:09:37,920 --> 00:09:39,536 That would give us an opportunity 191 00:09:39,560 --> 00:09:41,680 to actually eliminate malaria as a disease. 192 00:09:42,360 --> 00:09:46,296 So cheese, dogs and a pill to kill mosquitos. 193 00:09:46,320 --> 00:09:49,280 That's the kind of out-of-the-box science that I love doing, 194 00:09:50,160 --> 00:09:52,136 for the betterment of mankind, 195 00:09:52,160 --> 00:09:53,776 but especially for her, 196 00:09:53,800 --> 00:09:57,696 so that she can grow up in a world without malaria. 197 00:09:57,720 --> 00:09:58,936 Thank you. 198 00:09:58,960 --> 00:10:00,240 (Applause)