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3 new ways to kill mosquitoes | Bart Knols | TEDxMaastricht

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    (Mosquito buzzing)
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    (Swat)
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    Gotcha.
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    Mosquitoes.
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    I hate them.
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    Don't you?
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    That awful buzzing sound at night
    around your ears
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    that drives you absolutely crazy?
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    Knowing that she wants
    to stick a needle in your skin
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    and suck out your blood?
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    That's awful, right?
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    In fact, there's only one good thing
    I can think of when it gets to mosquitoes.
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    When they fly into our bedroom at night,
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    they prefer to bite my wife.
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    (Laughter)
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    But that's fascinating, right?
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    Why does she receive more bites than I do?
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    And the answer is smell,
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    the smell of her body.
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    And since we all smell different
    and produce chemicals on our skin
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    that either attract or repel mosquitoes,
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    some of us are just
    more attractive than others.
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    So my wife smells nicer than I do,
    or I just stink more than she does.
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    Either way, mosquitoes find us in the dark
    by sniffing us out. They smell us.
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    And during my PhD,
    I wanted to know exactly
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    what chemicals from our skin
    African malaria mosquitoes use
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    to track us down at night.
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    And there's a whole range
    of compounds that they do use.
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    And this was not going to be an easy task.
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    And therefore we set up
    various experiments.
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    Why did we set up these experiments?
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    Because half the world's population
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    runs the risk of contracting
    a killer disease like malaria
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    through a simple mosquito bite.
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    Every 30 seconds,
    somewhere on this planet,
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    a child dies of malaria,
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    and Paul Levy this morning,
    he was talking about the metaphor
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    of the 727 crashing
    into the United States.
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    Well, in Africa, we have
    the equivalent of seven jumbo 747s
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    crashing every day.
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    But perhaps if we can attract
    these mosquitoes to traps,
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    bait it with our smell,
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    we may be able
    to stop transmission of disease.
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    Now, solving this puzzle
    was not an easy thing,
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    because we produce hundreds
    of different chemicals on the skin,
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    but we undertook
    some remarkable experiments
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    that managed us to resolve
    this puzzle very quickly indeed.
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    First, we observed
    that not all mosquito species
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    bite on the same part of the body.
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    Strange.
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    So we set up an experiment
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    where we put a naked volunteer
    in a large cage,
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    (Laughter)
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    and in that cage, we released mosquitoes
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    to see where they were biting
    on the body of that person.
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    And we found some remarkable differences.
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    On the left here you see the bites
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    by the Dutch malaria mosquito
    on this person.
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    They had a very strong preference
    for biting on the face.
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    In contrast, the African malaria mosquito
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    had a very strong preference for biting
    the ankles and feet of this person.
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    And that, of course,
    we should have known all along,
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    because they're called
    mosqui-toes, you see?
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    (Laughter)
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    That's right.
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    (Applause)
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    And so we started
    focusing on the smell of feet ...
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    on the smell of human feet,
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    until we came across
    a remarkable statement in the literature
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    that said that cheese smells after feet
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    rather than the reverse.
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    Think of it.
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    And this triggered us
    to do a remarkable experiment.
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    We tried, with a tiny little piece
    of Limburger cheese,
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    which smells badly after feet,
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    to attract African malaria mosquitoes.
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    And you know what? It worked.
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    In fact, it worked so well
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    that now we have a synthetic mixture
    of the aroma of Limburger cheese
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    that we're using in Tanzania
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    and has been shown there
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    to be two to three times
    more attractive to mosquitoes than humans.
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    Limburg, be proud of your cheese,
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    as it is now used
    in the fight against malaria.
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    (Applause)
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    That's the cheese, just to show you.
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    My second story is remarkable as well.
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    It's about man's best friend.
    It's about dogs.
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    And I will show you how we can use dogs
    in the fight against malaria.
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    One of the best ways of killing mosquitoes
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    is not to wait until
    they fly around like adults
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    and bite people and transmit disease.
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    It's to kill them when they're still
    in the water as larvae.
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    Why?
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    Because they are just like the CIA.
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    In that pool of water,
    these larvae are concentrated.
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    They're all together there.
    They are immobile.
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    They can't escape from that water.
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    They can't fly.
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    And they're accessible.
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    You can actually walk up to that pool
    and you can kill them there, right?
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    So the problem that we face with this
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    is that, throughout the landscape,
    all these pools of water with the larvae,
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    they are scattered all over the place,
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    which makes it very hard
    for an inspector like this
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    to actually find all these breeding sites
    and treat them with insecticides.
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    And last year we thought very, very hard,
    how can we resolve this problem?
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    Until we realized that just like us --
    we have a unique smell --
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    mosquito larvae
    also have a very unique smell.
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    And so we set up another crazy experiment,
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    because we collected
    the smell of these larvae,
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    put it on pieces of cloth,
    and then did something very remarkable.
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    Here we have a bar with four holes
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    and we put the smell
    of these larvae in the left hole.
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    Oh, that was very quick.
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    And then you see the dog.
    It's called Tweed. It's a border collie.
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    He's examining these holes
    and now he's got it already.
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    He's going back to check
    the control holes again,
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    but he's coming back to the first one,
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    and now he's locking into that smell,
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    which means that now,
    we can use dogs with these inspectors
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    to much better find the breeding sites
    of mosquitoes in the field,
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    and therefore have
    a much bigger impact on malaria.
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    This lady is Ellen van der Zweep.
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    She's one of the best
    dog trainers in the world,
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    and she believes
    that we can do a lot more.
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    Since we also know that people
    that carry malaria parasites
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    smell different compared to people
    that are uninfected,
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    she's convinced that we can train dogs
    to find people that carry the parasite.
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    That means that in a population
    where malaria has gone down all the way
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    and there's few people
    remaining with parasites,
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    that the dogs can find these people,
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    we can treat them with antimalarial drugs
    and give the final blow to malaria.
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    Man's best friend
    in the fight against malaria.
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    My third story is perhaps
    even more remarkable ...
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    and, I should say, has never been shown
    to the public until today.
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    (Audience cheers)
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    Yeah.
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    It's a crazy story, but I believe
    it's perhaps the best and ultimate revenge
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    against mosquitoes ever.
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    In fact, people have told me
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    that now they will enjoy
    being bitten by mosquitoes.
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    And the question of course is,
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    what would make someone
    enjoy being bitten by mosquitoes?
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    And the answer I have right here ...
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    in my pocket --
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    (Laughter)
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    if I get it.
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    It's a tablet.
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    A simple tablet,
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    and when I take it with water ...
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    it does miracles.
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    Thank you.
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    Now, let me show you how this works.
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    Here in this box, I have a cage
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    with several hundred
    hungry female mosquitoes ...
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    (Laughter)
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    that I'm just about to release.
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    (Laughter)
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    Just kidding, just kidding.
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    (Laughter)
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    What I'm going to show you
    is, I'm gonna stick my arm into it
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    and I will show you
    how quickly they will bite.
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    There we go.
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    Don't worry, I do this
    all the time in the lab.
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    There we go.
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    OK.
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    Now, on the video --
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    on the video here,
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    I'm going to show you
    exactly the same thing,
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    except that what
    I'm showing you on the video
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    happened one hour after I took the tablet.
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    Have a look.
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    That doesn't work.
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    OK. Sorry about that.
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    I'm sticking in my arm,
    I'm giving them a big juicy blood meal,
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    I'm shaking them off,
    and we follow them through time
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    to see these mosquitoes
    get very, very sick indeed,
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    here shown in fast motion.
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    And three hours later,
    what we see at the bottom of the cage
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    is dead mosquitoes ...
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    very dead mosquitoes.
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    And I'm going to say,
    ladies and gentlemen,
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    we have swapped the cards with mosquitoes.
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    They don't kill us. We kill them.
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    (Applause)
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    Now --
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    (Laughter)
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    Maastricht, be prepared.
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    Now, think of what we can do with this.
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    We can actually use this
    to contain outbreaks
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    of mosquito-born diseases,
    of epidemics, right?
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    And better still,
    imagine what would happen
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    if, in a very large area, everyone would
    take this drug, for just three weeks.
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    That would give us an opportunity
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    to actually eliminate
    malaria as a disease.
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    So cheese, dogs and a pill
    to kill mosquitoes.
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    That's the kind of out-of-the-box
    science that I love doing ...
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    for the betterment of mankind,
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    but especially for her,
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    so that she can grow up
    in a world without malaria.
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    Thank you.
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    (Applause)
Title:
3 new ways to kill mosquitoes | Bart Knols | TEDxMaastricht
Description:

We can use a mosquito's own instincts against her. At TEDxMaastricht speaker Bart Knols demos the imaginative solutions his team is developing to fight malaria -- including Limburger cheese and a deadly pill.

This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at http://ted.com/tedx

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Video Language:
English
Team:
closed TED
Project:
TEDxTalks
Duration:
10:41

English subtitles

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