Sonia Shah: 3 reasons we still haven't gotten rid of malaria

184,823 views ・ 2013-09-12

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00:12
So over the long course of human history,
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the infectious disease that's killed more humans
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than any other is malaria.
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It's carried in the bites of infected mosquitos,
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and it's probably our oldest scourge.
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We may have had malaria since we evolved from the apes.
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And to this day, malaria takes a huge toll on our species.
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We've got 300 million cases a year
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and over half a million deaths.
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Now this really makes no sense.
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We've known how to cure malaria
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since the 1600s.
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That's when Jesuit missionaries in Peru
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discovered the bark of the cinchona tree,
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and inside that bark was quinine,
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still an effective cure for malaria to this day.
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So we've known how to cure malaria for centuries.
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We've known how to prevent malaria since 1897.
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That's when the British army surgeon Ronald Ross
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discovered that it was mosquitos that carried malaria,
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not bad air or miasmas, as was previously thought.
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So malaria should be a relatively simple disease to solve,
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and yet to this day, hundreds of thousands of people
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are going to die from the bite of a mosquito.
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Why is that?
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This is a question that's
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personally intrigued me for a long time.
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I grew up as the daughter of Indian immigrants
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visiting my cousins in India every summer,
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and because I had no immunity to the local malarias,
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I was made to sleep under this hot, sweaty mosquito net every night
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while my cousins, they were allowed to sleep
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out on the terrace and have
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this nice, cool night breeze wafting over them.
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And I really hated the mosquitos for that.
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But at the same time, I come from a Jain family,
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and Jainism is a religion that espouses
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a very extreme form of nonviolence.
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So Jains are not supposed to eat meat.
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We're not supposed to walk on grass,
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because you could, you know,
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inadvertently kill some insects when you walk on grass.
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We're certainly not supposed to swat mosquitos.
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So the fearsome power of this little insect
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was apparent to me from a very young age,
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and it's one reason why I spent five years as a journalist
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trying to understand, why has malaria
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been such a horrible scourge for all of us for so very long?
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And I think there's three main reasons why.
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Those three reasons add up to the fourth reason,
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which is probably the biggest reason of all.
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The first reason is certainly scientific.
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This little parasite that causes malaria,
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it's probably one of the most complex
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and wily pathogens known to humankind.
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It lives half its life inside the cold-blooded mosquito
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and half its life inside the warm-blooded human.
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These two environments are totally different,
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but not only that, they're both utterly hostile.
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So the insect is continually trying to fight off the parasite,
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and so is the human body continually trying to fight it off.
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This little creature survives under siege like that,
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but not only does it survive, it has thrived.
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It has spread. It has more ways to evade attack than we know.
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It's a shape-shifter, for one thing.
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Just as a caterpillar turns into a butterfly,
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the malaria parasite transforms itself like that
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seven times in its life cycle.
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And each of those life stages not only looks totally different from each other,
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they have totally different physiology.
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So say you came up with some great drug
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that worked against one stage of the parasite's life cycle.
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It might do nothing at all to any of the other stages.
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It can hide in our bodies, undetected,
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unbeknownst to us, for days, for weeks,
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for months, for years, in some cases even decades.
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So the parasite is a very big scientific challenge to tackle,
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but so is the mosquito that carries the parasite.
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Only about 12 species of mosquitos
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carry most of the world's malaria,
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and we know quite a bit about the kinds of
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watery habitats that they specialize in.
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So you might think, then, well, why don't we just
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avoid the places where the killer mosquitos live? Right?
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We could avoid the places where the killer grizzly bears live
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and we avoid the places where the killer crocodiles live.
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But say you live in the tropics
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and you walk outside your hut one day
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and you leave some footprints in the soft dirt
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around your home.
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Or say your cow does, or say your pig does,
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and then, say, it rains,
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and that footprint fills up with a little bit of water.
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That's it. You've created the perfect
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malarial mosquito habitat that's right outside your door.
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So it's not easy for us to extricate ourselves from these insects.
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We kind of create places that they love to live
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just by living our own lives.
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So there's a huge scientific challenge,
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but there's a huge economic challenge too.
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Malaria occurs in some of the poorest
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and most remote places on Earth,
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and there's a reason for that.
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If you're poor, you're more likely to get malaria.
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If you're poor, you're more likely to live
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in rudimentary housing on marginal land that's poorly drained.
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These are places where mosquitos breed.
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You're less likely to have door screens or window screens.
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You're less likely to have electricity
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and all the indoor activities that electricity makes possible,
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so you're outside more.
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You're getting bitten by mosquitos more.
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So poverty causes malaria,
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but what we also know now is that malaria itself
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causes poverty.
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For one thing, it strikes hardest during harvest season,
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so exactly when farmers need to be out in the fields
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collecting their crops, they're home sick with a fever.
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But it also predisposes people to death
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from all other causes.
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So this has happened historically.
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We've been able to take malaria out of a society.
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Everything else stays the same,
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so we still have bad food, bad water, bad sanitation,
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all the things that make people sick.
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But just if you take malaria out,
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deaths from everything else go down.
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And the economist Jeff Sachs has actually quantified
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what this means for a society.
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What it means is, if you have malaria in your society,
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your economic growth is depressed
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by 1.3 percent every year,
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year after year after year, just this one disease alone.
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So this poses a huge economic challenge,
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because say you do come up with your great drug
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or your great vaccine -- how do you deliver it
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in a place where there's no roads,
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there's no infrastructure,
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there's no electricity for refrigeration to keep things cold,
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there's no clinics, there's no clinicians
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to deliver these things where they're needed?
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So there's a huge economic challenge in taming malaria.
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But along with the scientific challenge and the economic challenge,
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there's also a cultural challenge,
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and this is probably the part about malaria
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that people don't like to talk about.
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And it's the paradox that the people
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who have the most malaria in the world
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tend to care about it the least.
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This has been the finding of medical anthropologists again and again.
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They ask people in malarious parts of the world,
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"What do you think about malaria?"
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And they don't say, "It's a killer disease. We're scared of it."
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They say, "Malaria is a normal problem of life."
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And that was certainly my personal experience.
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When I told my relatives in India
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that I was writing a book about malaria,
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they kind of looked at me like
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I told them I was writing a book about warts or something.
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Like, why would you write about something so boring,
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so ordinary? You know?
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And it's simple risk perception, really.
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A child in Malawi, for example,
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she might have 12 episodes of malaria before the age of two,
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but if she survives,
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she'll continue to get malaria throughout her life,
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but she's much less likely to die of it.
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And so in her lived experience,
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malaria is something that comes and goes.
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And that's actually true for most of the world's malaria.
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Most of the world's malaria comes and goes on its own.
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It's just, there's so much malaria
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that this tiny fraction of cases that end in death
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add up to this big, huge number.
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So I think people in malarious parts of the world
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must think of malaria the way
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those of us who live in the temperate world
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think of cold and flu. Right?
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Cold and flu have a huge burden on our societies
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and on our own lives,
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but we don't really even take
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the most rudimentary precautions against it because
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we consider it normal to get cold and flu
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during cold and flu season.
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And so this poses a huge cultural challenge in taming malaria,
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because if people think it's normal to have malaria,
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then how do you get them to run to the doctor
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to get diagnosed, to pick up their prescription,
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to get it filled, to take the drugs,
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to put on the repellents, to tuck in the bed nets?
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This is a huge cultural challenge in taming this disease.
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So take all that together.
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We've got a disease. It's scientifically complicated,
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it's economically challenging to deal with,
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and it's one for which the people who stand
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to benefit the most care about it the least.
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And that adds up to the biggest problem of all,
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which, of course, is the political problem.
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How do you get a political leader to do anything
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about a problem like this?
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And the answer is, historically, you don't.
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Most malarious societies throughout history
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have simply lived with the disease.
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So the main attacks on malaria have come
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from outside of malarious societies,
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from people who aren't constrained
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by these rather paralyzing politics.
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But this, I think, introduces a whole host of other kinds of difficulties.
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The first concerted attack against malaria
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started in the 1950s.
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It was the brainchild of the U.S. State Department.
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And this effort well understood the economic challenge.
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They knew they had to focus on cheap, easy-to-use tools,
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and they focused on DDT.
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They understood the cultural challenge.
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In fact, their rather patronizing view was that
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people at risk of malaria shouldn't be asked to do anything at all.
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Everything should be done to them and for them.
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But they greatly underestimated the scientific challenge.
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They had so much faith in their tools
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that they stopped doing malaria research.
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And so when those tools started to fail,
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and public opinion started to turn against those tools,
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they had no scientific expertise to figure out what to do.
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The whole campaign crashed, malaria resurged back,
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but now it was even worse than before
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because it was corralled into the hardest-to-reach places
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in the most difficult-to-control forms.
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One WHO official at the time actually called that whole campaign
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"one of the greatest mistakes ever made in public health."
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The latest effort to tame malaria started in the late 1990s.
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It's similarly directed and financed primarily
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from outside of malarious societies.
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Now this effort well understands the scientific challenge.
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They are doing tons of malaria research.
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And they understand the economic challenge too.
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They're focusing on very cheap, very easy-to-use tools.
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But now, I think, the dilemma is the cultural challenge.
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The centerpiece of the current effort is the bed net.
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It's treated with insecticides.
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This thing has been distributed across the malarious world
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by the millions.
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And when you think about the bed net,
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it's sort of a surgical intervention.
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You know, it doesn't really have any value
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to a family with malaria except that it helps prevent malaria.
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And yet we're asking people to use these nets every night.
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They have to sleep under them every night.
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That's the only way they are effective.
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And they have to do that
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even if the net blocks the breeze,
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even if they might have to get up in the middle of the night
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and relieve themselves,
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even if they might have to move all their furnishings
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to put this thing up,
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even if, you know, they might live in a round hut
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in which it's difficult to string up a square net.
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Now that's no big deal if you're fighting a killer disease.
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I mean, these are minor inconveniences.
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But that's not how people with malaria think of malaria.
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So for them, the calculus must be quite different.
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Imagine, for example, if a bunch of well-meaning Kenyans
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came up to those of us in the temperate world and said,
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"You know, you people have a lot of cold and flu.
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We've designed this great, easy-to-use, cheap tool,
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we're going to give it to you for free.
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It's called a face mask,
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and all you need to do is
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wear it every day during cold and flu season
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when you go to school and when you go to work."
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Would we do that?
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And I wonder if that's how people
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in the malarious world thought of those nets
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when they first received them?
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Indeed, we know from studies
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that only 20 percent of the bed nets
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that were first distributed were actually used.
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And even that's probably an overestimate,
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because the same people who distributed the nets
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went back and asked the recipients,
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"Oh, did you use that net I gave you?"
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Which is like your Aunt Jane asking you,
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"Oh, did you use that vase I gave you for Christmas?"
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So it's probably an overestimate.
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But that's not an insurmountable problem.
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We can do more education,
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we can try to convince these people to use the nets.
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And that's what happening now.
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We're throwing a lot more time and money
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into workshops and trainings and musicals and plays
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and school meetings,
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all these things to convince people
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to use the nets we gave you.
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And that might work.
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But it takes time. It takes money.
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It takes resources. It takes infrastructure.
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It takes all the things that that cheap,
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easy-to-use bed net was not supposed to be.
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So it's difficult to attack malaria from inside malarious societies,
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but it's equally tricky when we try to attack it
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from outside of those societies.
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We end up imposing our own priorities
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on the people of the malarious world.
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That's exactly what we did in the 1950s,
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and that effort backfired.
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I would argue today,
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when we are distributing tools that we've designed
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and that don't necessarily make sense in people's lives,
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we run the risk of making the same mistake again.
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That's not to say that malaria is unconquerable,
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because I think it is,
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but what if we attacked this disease
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according to the priorities of the people who lived with it?
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Take the example of England and the United States.
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We had malaria in those countries for hundreds of years,
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and we got rid of it completely,
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not because we attacked malaria. We didn't.
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We attacked bad roads and bad houses
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and bad drainage and lack of electricity and rural poverty.
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We attacked the malarious way of life,
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and by doing that, we slowly built malaria out.
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Now attacking the malarious way of life,
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this is something -- these are things people care about today.
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And attacking the malarious way of life,
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it's not fast, it's not cheap, it's not easy,
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but I think it's the only lasting way forward.
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Thank you so much.
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(Applause)
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About this website

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