- [Voiceover] So, once Malaria has been confirmed
by lab or by biochemical diagnosis treatment kind of has to
start right away to give the person the best chance of
survival, right, with as few complications as possible.
So, let's say we're gonna use antimalarial drugs to treat
the disease, right.
So, to make sure we're using the right drugs we'll need
to know a few things.
So, we need to know what type of plasmodium
is causing the infection, because some subtypes
will just respond to drugs that others might not.
We'll need to know how the patient's doing, right?
Is this an uncomplicated Malaria, right, with, you know,
flu-y symptoms, fevers, and chills that kind of stuff?
Or is this severe Malaria with systemic life threatening
symptoms?
We'll need to know what we're dealing with.
We'll also need to know if these parasites that are causing
the infection, we need to know if they're resistant
to any of our treatment.
Maybe the infection was picked up in, you know,
a part of the world known to have treatment resistant
Malaria.
So, there's a couple things we need to know
right off the bat before we start treatment.
So, let's say our patient over here he has uncomplicated
Malaria, and let's remind ourselves that uncomplicated
is still very serious, it can still be fatal.
And, our patient over here, let's say he has severe Malaria.
Notice that this guy, uncomplicated guy is just hanging
out at home, right, he's still really exhausted and flu-y
feeling, but he's at home.
But, severe Malaria guy over here he's in a hospital bed
and he's got an IV in and he's being monitored,
he's being totally looked after by the hospital staff.
And, that's because for uncomplicated guy over here
he can take his antimalarial drugs in pill form.
He can just take them at home.
But, severe guy, remember he's having systemic symptoms,
maybe his blood pressure is dangerously low or maybe
he's severely anemic, or maybe he has brain symptoms,
cerebral Malaria where he's having seizures or maybe his
brain just isn't controlling his breathing properly,
or maybe he's gone into a coma.
So, he's in a hospital because in addition to getting
antimalarials, which he'll get through this IV line
here, he won't get them in pill form like this guy over here
he'll need constant medical care to make sure that he
survives, and with as few permanent complications
as possible.
So, let's talk about the types of medicines that can cure
a Malaria infection.
So, remember that there's essentially two stages
of infection with Malaria.
There's a liver phase where sporozorites infect
your liver cells and multiply into thousands of merozoites.
And then, there's a red blood cell phase where these
little merozoites break out of your liver cells
and infect your red blood cells.
And, once they're inside your red blood cells
they turn into what are called trophozoites.
They hang out for a while and then they multiply
into thousands more merozoites again.
So, we have medications that can destroy these parasites
at any of these stages, which is good.
So, for uncomplicated Malaria the person usually gets
treated with combination therapy which means that they
take a few different drugs to treat their Malaria.
So, they take usually two to three drugs
because if you just use one drug to treat a Malaria
infection well pretty quickly the parasites are gonna figure
out how to become resistant, right, how to avoid being
killed by that one drug.
And, in fact, this is already a huge problem,
there's already a lot of drug resistance that's cropped up
in different parts of the world.
So, that's why it's super important to use combination
therapies to make sure that no potentially mutated
parasites survive after treatment.
Otherwise one day we just won't have any drugs left
that work.
So, the recommended combination for treating uncomplicated
Malaria is called ACT: artemisinin
combination therapy.
And, artemisinin here is actually the name of a plant
that we get this main drug in this combo from.
The drug is called Artesunate and we get it from
the artemisinin plant.
So, Artesunate does a few things, it creates a really
toxic environment in the parasites that can kill them.
And, it interferes with some pretty important proteins
on the plasmodium surface that allow them to get
their nutrients.
So, that makes it hard for them to stay alive too.
And, the reason that ACT is built around this Artesunate
drug here is because Artesunate is really, really effective
against all the types of plasmodium.
And, because there's not really much resistance to it
right now, which is great.
So, the standard combo is Artesunate, plus some other drug
with a different mechanism of action.
So, for example one that's commonly used is
Mefloquine.
Mefloquine here, which disrupts the acid base
balance in the parasite and that's often lethal
to the parasite.
Or, sometimes you'll get a combo of two synergistic drugs
Sulfadoxin and Pyrimethamine, which stops the Malaria
from being able to replicate its DNA properly
which means it can't really reporoduce very well
in our bodies.
These are just examples, there's other possibilites
as well, though.
So, what I just told you all this ACT stuff, that's
the standard treatment of uncomplicated Malaria
caused specifically by a plasmodium falciparum.
ACT is really good at clearing a falciparum infection from
the bloodstream.
Plasmodium vivax, on the other hand, that has to be
treated in a different way.
So, for the blood stage you could still use ACT
just like with falciparum, or often a drug called Chloroquin
is used, but there's a fair amount of resistance
to Choloroquin amongst Malaria parasites
nowadays, mostly in south east Asia.
But, how does Choloroquin work?
Well, Malaria parasites feed on blood, they actually like
the hemoglobin component of red blood cells,
that's why they have such a blast in our bloodstream.
But, when they're busy digesting the hemoglobin
from a red blood cell they release the heme part
of the hemoglobin molecule, right.
So, they're just kind floating around because they don't
wanna eat it, they just eat the globin part.
And, free heme floating around here is actually
toxic to both them, the parasites, and to the red blood
cell that they're hanging around in.
So, because they wanna stick around in the red cell
for a while and, you know of course, because they wanna live
the parasites convert this heme into crystals of hemozoin,
which is not toxic to the cell or to them.
So, Cholorquin and actually Mefloquin does this as well,
these drugs prevent the parasites from converting
the toxic heme into nontoxic hemozoin crystals, right?
So, all of the resulting heme it builds up and it just makes
the environment really toxic and then the parasites
end up dying, which is great.
So, that's the blood stage with plasmodium vivax
but vivax is interesting though, it likes to hang out
in the liver as well in a dormant phase, unlike falciparum.
Falciparum sort of gets on with it and causes super
severe infections pretty quickly, where as vivax, right,
while it can still be really severe it takes it
a bit slower so it likes to transform into what are called
hypnozoites.
And then, these hypnozoites take naps in the liver cells
for extended periods of time.
So, it's kinda like having a chronic Malaria infection
with vivax.
So, you have to kill the liver parasites, and you can do
that with Primaquine which is actually effective against
all types of Malaria, but we especially like it
for how it deals with the vivax hypnozoites.
Anyway, the Primaquine works by blocking oxidative
metabalism in these hypnozoites in the liver.
So, it stops them from being able to make enough energy
to survive, so they die.
Now, those are just the basic ideas of how you treat
uncomplicated falciparum and vivax.
You can see that there's quite a few different things
to think about.
But, if someone has severe malaria, right this guy
over here, there's pretty much one thing that you always do.
You stick in an IV, an intravenous line, right?
And, you give the person Artesunate, remember that main
drug in the ACT combo therapy.
And, they can't take it in pill form, they need it to go
straight into their bloodstream because there's not really
any time to fiddle around with pills and all that.
So, besides the IV Artesunate the person willl need
supportive treatment, remember in severe Malaria
the person might be having seizures, or they might
be in a coma, or they might not be able to breathe
on their own.
So, they're gonna need respiratory support, and they'll
probably also be really dehydrated so they'll need fluids
and electrolytes as well.
So, what sort of prognosis can you expect
with Malaria treatment?
Well, if you get proper treatment then usually you can
expect a full recovery, especially with uncomplicated
Malaria.
And, this is all usually true with severe Malaria too,
but it's important to keep in mind that severe Malaria
can progress really quickly and it can also be a bit
unpredictable.
So, even with treatment and intensive care
it still often still leads to death.