Extracting Venom From Deadly Snakes | 24 Hours With | BBC Earth


[Yussef] This is nerve wracking.
And this is their job.
They do this all the time.
I’m Yussef Rafik, and I’m a zoologist and former zookeeper.
I spent years working with animals, so I know how tough but also rewarding
it can be.
But now I want to try some of the more unusual wildlife jobs out there
and meet the dedicated people behind them to find out if I have
what it takes.
In this building live nearly 200 of the world’s
most deadly snakes looked after by a dedicated team of experts
who put their lives on the line every single day in order to work
at the very cutting edge of antinom research.
And I’m going to be spending 24 hours with them.
This is the Liverpool School of Tropical Medicine,
where I’ll be meeting with herpetologist Paul,
who has a lifelong interest in collecting venom from deadly snakes.
Also known as snake milking,
this process is harmless when done correctly, but it’s essential
for studying venom and creating antinoms which save thousands of lives each year.
Today, I’ll be joining the team for some venom extractions.
But first, I want to ask Paul a few questions.
Hello.
[Yussef] So how long have you worked with snakes?
I started my career in the ’80s, originally as a zookeeper at Chester Zoo,
and I’ve been here for nearly the last 30 years.
That’s incredible, obviously because everyone’s aware
that venomous snakes are dangerous.
How much of an impact do they have around the world?
Well, we estimate there’s about 2.7 million envenomings a year.
About 138,000 deaths worldwide
and probably around about 400,000 disabilities
resulting from those bites.
Have you ever been bitten?
Unfortunately, yes.
It is an occupational hazard.
I’ve been hospitalized three times in my career, but we’re very,
very fortunate in having a hospital literally across the road here.
And some of the world’s best doctors
that are capable of dealing with snake bites here in Liverpool.
So in a way, if you’re going to get bitten by a snake, this is the best place.
If you’re going to do it, this is the place to do it. Okay.
Okay, I mean, we’re going to meet some of these venomous snakes,
and it’s a it’s making me a little bit nervous.
Absolutely no worries at all.
You’re in good hands.
In safe hands. That’s good to know.
[Paul] Right, we’ll go and check room four to start with.
[Yussef] Okay.
[Paul] And then we’ll do the environmental checks.
I’m going to have a look at some of the snakes in this room.
Amazing.
Wow.
[Yussef] Oh, wow. Cobra straight away.
[Paul] On this side of the room, we’ve got mainly forest cobras.
These are
a very dangerous cobra.
African species.
[Yussef] Snakes evolved venom to help them hunt.
When a snake is feeling threatened, venom is also handy as a defense,
which is why so many people get bitten each year.
All of the snakes in this collection have deadly venom,
but only one has been a confirmed killer.
What’s the most interesting or unique way that they’ve come into your possession?
[Paul] When I started, we actually had a forest cobra in the collection.
And the story behind that one was it was used by mafia gangsters
to murder somebody in a hotel room in New York.
And so this person was found dead in a hotel room.
And the police obviously got involved.
And the forensic scientist, they did an analysis, sent us some tissue.
So we were able to analyze it and discover
the venom of a forest cobra was the cause of death.
And the Bronx Zoo captured the forest cobra and sent it to us.
So we ended up with not only a known killer,
in a collection, but also tissue samples from the victim.
And we were able to pair them open confirmed cause of death.
So that was a mafia hit in the early ’90s.
[Yussef] That’s incredible. Wow.
After meeting the snakes in
Paul’s care, we make our way to the procedure room.
Once we’ve done some prep, Paul and Ed begin by extracting venom from
a puff adder.
So for safety reasons, I can’t be in the room with them right now
because as you can see, it’s a loose, venomous snake.
Quite aggressive. So I’m quite thankful that I’m out here right now.
The puff adder is a viper that is thought to be responsible for causing
the most snake bites in Africa, of which 50% are fatal, if untreated.
And this one is feeling especially grumpy.
[Ed] Oh, dear me.
Right.
Okay.
This is nerve wracking.
This is their job.
They do this all the time.
The team works hard to gain control before I enter the room.
Now that
it’s safely restrained, it’s time to extract the venom.
[Paul] Okay.
Yeah,
Being naughty this one.
[Ed] Everyone ready?
All right, let’s go for it.
[Yussef] Oh, my goodness. Look at that.
Look at those fangs.
That was a bite, wasn’t it?
[Paul] Yeah.
[Yussef] Imagine if that was your skin as well.
Look at the damage done to that membrane.
Snake venom is a complex cocktail of toxins.
The deadliest type of venom, like that from a black mamba, shuts down
the nervous system and can kill a human in as little as 20 minutes.
Neurotoxic venom can be delivered without a lot of pain.
So some people might not realise
they’ve been bitten until they can feel the symptoms.
Next, Paul and Ed tackle the spectacled cobra,
which requires slightly more wrangling.
Cobra venom is
typically cytotoxic, which means the bites kill cells causing severe skin
blistering and can lead to loss of limbs if untreated.
This means that even if someone survives
the bite, complications can leave people with life-changing injuries.
[Ed] These guys like to hold on.
[Yussef] We finished with a saw scaled viper.
Despite being the smallest species in the room,
even a weak by that only injects a small amount of venom
could still be enough to kill multiple people.
[Paul] There we go.
[Yussef] Venom extracted, Ed tells me a little more about one of our samples.
There is some of the venom from the animal.
That is probably enough to kill someone.
So it’s a potent neurotoxin venom.
That’s more than enough for our research.
And it is a descending paralysis in there.
So once it hits the lungs,
if you haven’t got something to ventilate or manually ventilate the lungs.
Unfortunately, a lot of people will suffocate.
And that’s the rapid onset of these venoms.
[Yussef] It’s terrifying
If you can get to a hospital though, the treatment is very effective.
[Yussef] How long have you got?
We usually talk about the golden hour.
But as soon as you can get to a hospital, is the best.
[Yussef] Now that the venom is safely stored, I can carefully transport it to a lab
in another part of the building where the team research antivenom.
I have a few questions for Cassie about her research and about what
antivenom researchers are hoping to achieve long term.
Antivenoms are made by injecting snake venom into horses
and then using that immune reaction to make an antidote.
It’s a process that’s more than 100 years old,
and scientists are looking for better alternatives.
So you mentioned that you work on making novel antivenoms.
Why is it that we need new ones?
[Cassie] For one, it’d be nice to move away from the animals
because different animals respond differently.
So we’d like a consistent product in the future.
We hope that we’ll be able to use protein expression systems
like bacteria, yeast, mammalian cell culture, etc.
that we can then produce antibodies from.
And then we will no longer need to use the animals.
How expensive is antivenom?
So it’s about for Sub-Saharan Africa
it’s 100 to 200 USD per vial.
But if you’re bitten by a snake, it’s
a very severe bite, you’ll actually need multiple vials.
And so it can easily go up over 1000,
which is considerably more than a farmer that’s working is making in that region.
In fact, snake bite really impacts the impoverished communities the greatest.
So that’s why your work is so important then,
because it’s helping with that issue.
Exactly. And reduce the cost of antivenom.
[Yussef] Yeah. Brilliant.
It’s been absolutely incredible to spend time with the team here.
And it’s amazing to think
that the venom processed in this lab goes on to save lives all around the world,
and that through this research, antivenom for the world’s deadliest snake bites
could one day be accessed more easily and affordably by those who need it most.
3 views

답글 남기기

Shopping Cart
/classroom/
https://talkingedu.com/product/course-registration/
https://us06web.zoom.us/j/8929527091?pwd=VUpTS3ZvNWFSbnpWSXVodmJJQkpLdz09
https://us05web.zoom.us/j/5080948583?pwd=f2mBHaCSjQ0jB4CSsrrCzm1WwnanIi.1
https://open.kakao.com/o/sbFCSNEf