
The debate over whether to use genetically modified mosquitoes to fight malaria - fluxic
https://www.vox.com/science-and-health/2018/5/31/17344406/crispr-mosquito-malaria-gene-drive-editing-target-africa-regulation-gmo
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RcouF1uZ4gsC
>Somewhere between 438,000 and 720,000 people were killed by the parasite in
2015. Seventy-two percent of those were kids younger than 5,

Sub Saharan Africa has a population of roughly 1 billion people. So this is
about 1/2000 of the population that die every year from malaria. If this was
happening in the US, say 150,000 people a year were dying from malaria every
year, including 100,000 children, do you really think there would be this huge
debate about wiping out these malaria species using CRISPR?

Wiping out disease carrying mosquitoes would be one of the best things that
could be done for global health. It would disproportionately benefit poor
countries in general and children in particular. It is a shame that we as
humanity are not making an all out push to eliminate these disease carrying
mosquitoes.

~~~
scarmig
Moral thought experiment:

Most scientists are attempting to build a public consensus around using gene
drives as a public health measure. It might be possible, though, for a single
rogue scientist to introduce a self sustaining gene drive that could eliminate
malaria, without seeking permission from any people, governments, or
organizations.

If you could do it, would you?

~~~
kpil
I would.

There are thousands of other species of mosquitos. I don't think there would
be any noticeable consequences at all after a while.

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crankylinuxuser
I thought we did similar modifications to the screw-worm fly
[https://en.wikipedia.org/wiki/Cochliomyia_hominivorax](https://en.wikipedia.org/wiki/Cochliomyia_hominivorax)

If I remember the procedure better, they radiated thousands of pounds of males
so hey were sterile. They evidently only mate once, so it destroyed the
population. I don't remember any real dissent discussion. The negatives of
getting rid of them were minor compared to the pain and suffering this
parasite introduced.

They are much more of what we think of as "tropical disease/parasite". I'd
warn anyone looking at more detailed pictures other than wikipedia I linked.

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Jedd
I recall reading about this idea (but not using CRISPR, natch) in New
Scientist back in the 1990's.

They covered off the precautionary principle / unintended consequences concern
by proposing to retain a breeding stock of the target species in a closed
system (say a greenhouse).

You'd be looking at a few years to deplete or render extinct the wild stock,
during which time you could be sure the malaria pathogen was absent from your
breeding stock.

Once malaria, and the modified mosquitoes, are confirmed absent from the wild,
you have the option to re-introduce. Naturally the option also exists at any
earlier time if the species turns out to be more important than originally
determined.

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sametmax
Given that malaron can actually cure Malaria (and not just prevent it as most
people think) by killing the plasmodium directly in the liver, I think all the
money for all the projects against malaria would be better invested in
creating a dedicated african run factory to make those locally and cheap.

Or planting a lot of Artemisia annua, since both the CNRS and the Gates
foundation now recognize this plant is a good alternative.

Ending malaria may take decades. We can prevent millions of people from dying
now.

~~~
tzumby
Also Malerone is not good on your liver and does not give you 100% protection.
I honestly never took my malerone while I travelled in a Malaria risk zone
based on the stories I heard about the side effects.

~~~
djsumdog
I'm not sure if it was Malerone, but I think some Malaria prevention
treatments before travelling to Asia in the late 90s. It had some pretty bad
side-effects. I didn't get the weird dreams, but it affected my body enough
that I just stopped talking it.

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api
Why is this a debate? Seriously.

There probably wouldn't be a debate if malaria were a big problem here.

~~~
madaxe_again
That may well be what ultimately tips the balance, sadly - as climate change
extends the range of anopheles and friends, associated tropical diseases
including Malaria will start to appear in Europe and the US.

~~~
Fomite
People forget that the reason the CDC is in Atlanta is mosquito control,
particularly for malaria. Philadelphia had yellow fever outbreaks.

These aren't diseases we worry about in the U.S. due to the largest public
health infrastructure programs in the world.

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Dowwie
We need this for ticks..

~~~
HumanHater
... and for bed bugs, and for fleas, and also for basically every insect that
feeds on mammal blood. They are important vectors of transmitting a whole lot
of diseases, some of which already dangerous to humans while others could
easily mutate to become ones. We are already eradicating a lot of species. May
as well exterminate bad ones. There are no ethical problems because no sane
person feels bad about killing ticks. These species probably don't have any
important ecological role (well maybe they speed up evolution a little bit,
but in that case screw evolution). And in case anything goes wrong
repopulating the whole globe with them would take no time.

~~~
andrewl
I agree. I would not mourn if ticks were eradicated.

Off the top of my head the only ecological role I can think of for them is as
food for tick-eating birds. But I don't think there are any birds that subsist
_exclusively_ on ticks, so they'd probably be all right.

And for our general literacy, I want to point out that ticks are arachnids,
not insects.

~~~
s0rce
Possum's also eat ticks.

~~~
BenjiWiebe
But they definitely don't _only_ eat ticks.

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org3432
Best line:

"I don't look at it [nature] as this morally benevolent place, it's a horror
show"

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raphinou
The article says malaria was eradicated in France. Anyone knows how? Why can
it not be replicated in africa?

~~~
vilhelm_s
Google shows this article about eradication of malaria in Corsica after WWII:
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2927611/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2927611/)
. The mosquito population was suppressed by draining marshes and by spraying
breeding grounds with insecticides such as DDT. If you disrupt the mosquito
population for a few years, the malaria parasite will die out since it needs
to be transmitted to humans or other animals as part of its life cycle.

The same thing was done in the U.S., where malaria used to be endemic until
the 20th century. [http://dcmosquitosquad.com/history-of-malaria-in-the-
usa/](http://dcmosquitosquad.com/history-of-malaria-in-the-usa/)

~~~
maxerickson
The malaria that infects humans only infects humans, which is simpler than if
you also have to deal with animal reservoirs.

~~~
mkstowegnv
Unfortunately "three human Plasmodium parasites" have been found in
chimpanzees.

"If malignant malaria were eradicated from human populations, chimpanzees, in
addition to gorillas, might serve as a reservoir for P. falciparum."

[http://www.pnas.org/content/107/23/10561](http://www.pnas.org/content/107/23/10561)

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sxates
I'm unclear how the modified mosquitoes replicate and spread if the genetic
alteration sterilizes them. Do you just have to continue releasing the GMO
versions, or is it not entirely effective, or what am I missing?

~~~
dan353hehe
There were two different kind of mosquitos mentioned in the article.

The one you are talking about are sterile males. All they do is compete with
the unmodified wild males, and can depress the population. As the mutation
isn't passed onto any future generations, new males have to be continuously
released. I remember reading somewhere else that this is already done in some
places ( but I can't remember where I read it, so don't quote me on that ).

The other kind mentioned in the article are non-sterile mosquitoes designed
with a trait, and paired with another set of genes that cause almost all
offspring to carry the same traits. I think the article mentioned around 95%
of the first generation would carry the change.

Pair that with a trait that causes more children to be male then female, and
the population could be suppressed by only releasing one batch of altered
males.

To me it sounds like a really good idea, but as mentioned in the article, once
released there wouldn't be any way to really control where it spread.

~~~
matte_black
If we completely fuck up couldn’t we just release a new breed of GMOs?

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petters
> “To be honest with you, if there were some kind of emergency and one
> absolutely needed to do it, we could pretty much do it.”

I can not understand this comment. How is 438,000 annual deaths not an
emergency!? We _DO_ absolutely need to do it!

~~~
UncleEntity
Two words: unintended consequences.

We humans don't really have a very good track record of dealing with the
things Nature throws at us as can be seen with countless examples invasive
species (imported to solve some problem or other) wrecking havoc on native
species, super-germs &etc.

I seem to recall reading that mosquitos are a staple food source for birds or
bats or something, what could possibly go wrong with killing them all off?

Humans have a natural immunity to malaria but nobody is saying we need to
genetically modify everyone to have sickle cell anemia.

~~~
DoreenMichele
_I seem to recall reading that mosquitos are a staple food source for birds or
bats or something, what could possibly go wrong with killing them all off?_

I am guilty of not reading the entire discussion here, so I apologize if this
is a derail, but historically they outright eradicated the mosquitoes on some
island... Which led to other things dying that ate the mosquitoes... Which led
to yet more things dying.

I am failing to find a source, but maybe this blog post references it:

 _During WWII the Navy (which had a large base on the island) sprayed the
village heavily with DDT to cut down the mosquito population. As you might
imagine, DDT killed the mosquitoes...and most of the frogs, and is suspected
of contributing to a number of cancer deaths on Ocracoke._

[https://villagecraftsmen.blogspot.com/2011/09/mosquito-
contr...](https://villagecraftsmen.blogspot.com/2011/09/mosquito-control.html)

~~~
modeless
DDT affects a lot more than just mosquitos. A gene drive wouldn't even kill
all mosquitos, just the specific ones that spread human diseases. You can't
compare the effects.

~~~
djsumdog
DDT was labeled as safe. It was sprayed on kids at swimming pools. Now we know
it weakens birds eggs, and causes birth defects.

It's not a matter of it this genetic modification would have consequences, but
what will those consequences and side effects be?

Our ecosystem is insanely complex, as show by the Biosphere II project. You
can't just try to surgically alter one part without lots of unintended effects
down the line.

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delbel
Another way to eliminate malaria is to modify it so that it kills the host,
eventually eliminating the ability of malaria to replicate and go to
extinction. I am not seriously suggesting this, but this is how nature works.
There are unknown diseases in the past that have extincted themselves this
way.

~~~
bilbo0s
How?

I can't speak with authority on many subjects, but as it happens, medicine is
one that I maintained a deep familiarity with in a past life. (Medical and bio
tech startups.)

There are over 200 surprisingly different species of Malaria. Humans are
affected by five or six of them if I'm remembering everything correctly. Here
is the thing, the number of species of birds, bats, antelope, monkeys, etc
affected by those malaria strains is legion. So here's your problem in
extremely simplified layman's terms, how do you make malaria kill ALL of its
potential hosts? Then there is the question of Anopheles. Will your
modifications kill that species as well? How do you stop the other 194 or 195
species of malaria from mutating to affect humans? Etc etc etc.

Continuing with overly simplified explanations, malaria has learned to
"survive" over the past few million years. There are many parasites out there
and I'd argue that malaria is far and away among the most savagely cunning in
this respect.

What you propose is akin to the jedi handwave-y manner that people propose we
"cure" cancer. It really is just not as simple as that. Historically, people
have always found themselves to be "really, really, really close"...

and that last 1% never materializes.

~~~
dogma1138
We’ve managed to eradicate malaria in many parts of the world without any
consequences, sure other strains may mutate but so far they haven’t. If they
do we’ll figure out how to deal with them when that happens.

Malaria isn’t the first parasite we’ve eradicated some of them we’ve
eradicated globally and hopefully it won’t be the last.

The biggest problem isn’t the how but it’s how to do it in Africa where the
infrastructure and the stability of governments across the entire region makes
it a hard task to accomplish.

~~~
UncleEntity
> We’ve managed to eradicate malaria in many parts of the world without any
> consequences...

As far as I know we've never eradicated _anything_ by modifying genes which is
the part most people are concerned with.

Sure, drain the swamps and/or use whatever methods worked in the past but
think twice before releasing mosquitos into the wild which have the
unfortunate side effect of turning crocodiles into Godzilla with a single
bite. I've seen the movies and <<spoiler alert>> it doesn't turn out well.

~~~
dogma1138
Scientifically illiterate people are scared of GMOs in other news water is
wet.

Also in several places malaria was eradicated using engineered mosquitos sure
we didn’t use gene editing but rather much more coarse tools like radiation.

We’ve been producing GMO for 15 millennia if anyone thinks that throwing sperm
at the wall or irradiating seeds is somehow not genetic engineering they need
to get their facts in order.

