
Malaria Drug Won’t Work for Much Longer - valhalla
https://fivethirtyeight.com/datalab/the-nobel-winning-malaria-drug-wont-work-for-much-longer/
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searine
Not necessarily.

Current prevalence of resistance to artemisinin is mostly due to what happened
shortly after the drugs discovery. That is, wide-spread single-mode-of-action
use. This was due to uncontrolled over-the-counter use in South East Asia,
which in recent years has been curtailed.

While this still happens, the WHO has gotten much much better at making sure
combined therapies are used, which is the essential bit to controlling
resistance.

The only tool we have to combating biological resistance (in any organism) are
combined therapies. Doing so hijacks the mathematics of natural selection to
make it almost impossible to evolve resistance (given high enough stacks of
modes-of-action and complete treatment courses).

As the graph in the article shows, artemisinin resistance is still mostly
contained to where it originally evolved (cambodia). Given careful management,
we can expect slow spread, if any at all.

Fighting malaria isn't a one-punch win. It is a marathon, but one that we are
very slowly winning. The disease is trending downwards and we are finally
making in-roads into the most endemic regions. This slow reduction in the
disease burden worldwide makes resistance harder and harder for the parasite
to evolve.

Drug resistance is deadly serious, but I'm not as pessimistic as this article.
Given proper tracking of resistance, and management, we'll easily have several
more decades of artemisinin use.

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BurningFrog
It's very hard for me to believe combined therapies can beat evolution.

I _can_ believe that it takes evolution longer to adapt to it.

Of course I don't even know what "combined therapies" is, so I'm probably
wrong. What am I missing?

~~~
searine
>It's very hard for me to believe combined therapies can beat evolution.

Obviously the faster an organism mutates/replicates the harder it is to
slow/stop evolution. HIV for example is "worst case scenario" but with
combination therapies we've managed to make HIV a treatable disease.

At the end of the day it all boils down to one hard fact. An organism can't
evolve if it is extinct. Selection works by causing deaths in a population (ex
selecting those which live on). If you raise the "cost of selection" so high
that an organism can't pay the cost in deaths, the population goes extinct.

As a rule of thumb, to fix an adaptive change, it takes 20 times the
population in deaths. So if the current population is 1000, it'll take 20,000
deaths (and by deaths I mean removing an unfit allele from the population)
over many generations to fix that adaptive allele.

>Of course I don't even know what "combined therapies" is, so I'm probably
wrong. What am I missing?

Therapies or methods that employ more than one independent mode-of-action. Ex:
Two drugs given at the same time.

This forces the organism to adapt to two things at once, doubling the cost of
selection. As you increase modes of action, the cost rises to the point that
it is impossible to adapt before the population goes extinct.

~~~
saurik
(Serious question: "doubling", or "squaring"?)

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sdenton4
Hm..... There's only two studies in Cambodia, though. One of them apparently
had a faillure rate of about 17%, which makes me think the other study had a
failure rate of about 5%, to get a median of ~12% seen in the graph. Couldn't
the high failure rate in Cambodia just be an artifact of an outlier study?
Nearby Laos also has a low failure rate. Unfortunately, I don't see Thailand
on the list, which would be another nearby country to compare with...

~~~
dogma1138
More likely is that the studies were done in different regions of the country
which have different parasite strains.

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baldfat
Since I have family that lives in Zambia and my daughter was there for three
months this is scary. Mosquito born diseases kill more people than any other
animal on earth. about 600,000 a year.

[http://www.gatesnotes.com/Health/Most-Lethal-Animal-
Mosquito...](http://www.gatesnotes.com/Health/Most-Lethal-Animal-Mosquito-
Week)

This could go MUCH MUCH higher.

~~~
bdchauvette
I'm not sure about other countries, but in Zambia at least the malaria rates
are not spread uniformly around the country [1]. If your family is in Lusaka,
for example, both they and your daughter should be pretty safe, especially if
they take precautions like sleeping under a net.

You probably already know this, but if your daughter shows any symptoms of
malaria, make sure you tell the examining physician that she's just returned
from an area that is known to have malaria. It's often one of the first things
doctors test for here in Zambia, but if you live in an area without endemic
malaria, they might not test for it at all.

[1]: [http://www.who.int/malaria/publications/country-
profiles/pro...](http://www.who.int/malaria/publications/country-
profiles/profile_zmb_en.pdf)

~~~
chimeracoder
> You probably already know this, but if your daughter shows any symptoms of
> malaria, make sure you tell the examining physician that she's just returned
> from an area that is known to have malaria. It's often one of the first
> things doctors test for here in Zambia, but if you live in an area without
> endemic malaria, they might not test for it at all.

Also, for the blood test, make sure she actually has a fever when the blood is
drawn.

Malaria (in the initial stages) may have a fever that comes and goes. The test
has much higher false negative rates if the blood sample is drawn when the
patient does not have a fever.

Doctors in areas where malaria is endemic generally know this, but doctors
elsewhere may not. If she has any signs of a fever for the next ~2 months,
it's best to get a blood sample drawn right away. Malaria is much more
treatable when detected early.

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placeybordeaux
Cambodia is highlighted here, but what isn't mentioned is that is
specificially the border region of Thailand and Cambodia. I find that
specifically worrying given the amount of travel that Thailand gets from
around the world.

I remember reading a story a couple years ago of Thais crossing the border
into Cambodia where artemisinin was cheap and unregulated, but I can't find
it.

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jnardiello
Resistance IS a big deal. I've lost my grandfather last monday due to
nosocomial pneumonia (essentially, pneumonia resistant to all existing
antibiotics).

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exar0815
Well, Malaria was once shortly before extinction. Then some stupid alarmists
decided to start a campaign against DDT...

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jlebrech
Does that also mean Daraprim's only use will be for AIDS shortly?

~~~
ksenzee
Sulfadoxine-pyrimethamine is already unusable for malaria, except in
combination with other drugs, because of high levels of resistance. This has
been the case for years.

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buggerball
Johns Hopkins is developing a mosquito where the virus can't be transmitted,
secondly the drug was developed in the 50s so the effective life of the drug
at only ... only 70 years of use to just show slowness recently. With the
research pace, the variation of reintroduced genetics will be less that 10. We
are fine.

