WEBVTT

00:00:00.000 --> 00:00:05.610 align:middle line:90%


00:00:05.610 --> 00:00:07.500 align:middle line:84%
I have with me here
Daryl, who's going

00:00:07.500 --> 00:00:10.230 align:middle line:84%
to tell us about his research
into the transmission

00:00:10.230 --> 00:00:12.050 align:middle line:90%
of cholera.

00:00:12.050 --> 00:00:16.079 align:middle line:84%
So Daryl, I thought cholera
was a disease of the past,

00:00:16.079 --> 00:00:18.060 align:middle line:90%
is it still a problem now?

00:00:18.060 --> 00:00:20.310 align:middle line:84%
So you're right in
that cholera has

00:00:20.310 --> 00:00:22.920 align:middle line:84%
been a scourge since
at least the 1800s.

00:00:22.920 --> 00:00:24.900 align:middle line:84%
So six pandemics
of cholera, we're

00:00:24.900 --> 00:00:28.500 align:middle line:84%
currently in the seventh
pandemic started in 1960.

00:00:28.500 --> 00:00:31.080 align:middle line:84%
It's the worst pandemics
we've seen of cholera yet,

00:00:31.080 --> 00:00:34.260 align:middle line:84%
the current situation in Yemen,
where the epidemic is quickly

00:00:34.260 --> 00:00:37.320 align:middle line:84%
reaching 1 million
people absolutely

00:00:37.320 --> 00:00:39.840 align:middle line:84%
is a reminder that cholera
has a strong foothold

00:00:39.840 --> 00:00:41.440 align:middle line:90%
in the modern world.

00:00:41.440 --> 00:00:43.440 align:middle line:90%
So how does cholera spread?

00:00:43.440 --> 00:00:45.660 align:middle line:84%
So cholera is the
classic example

00:00:45.660 --> 00:00:49.590 align:middle line:84%
of a waterborne disease, so
faecal contamination of water

00:00:49.590 --> 00:00:52.110 align:middle line:84%
sources, and people
get this by ingesting

00:00:52.110 --> 00:00:55.650 align:middle line:84%
the water contaminated with
the real cholera or food that's

00:00:55.650 --> 00:00:58.890 align:middle line:84%
been prepared with
contaminated water.

00:00:58.890 --> 00:01:02.040 align:middle line:84%
And so are there typing
schemes available

00:01:02.040 --> 00:01:05.400 align:middle line:84%
that allow people to
track how cholera spreads.

00:01:05.400 --> 00:01:07.500 align:middle line:84%
Yeah, so historically,
we've used

00:01:07.500 --> 00:01:11.580 align:middle line:84%
serotyping of the O-antigen
and the presence of the cholera

00:01:11.580 --> 00:01:14.190 align:middle line:84%
toxin which is
actually anaphase.

00:01:14.190 --> 00:01:15.930 align:middle line:84%
Other typing
techniques that we've

00:01:15.930 --> 00:01:19.290 align:middle line:84%
used our PFG or
ribotyping, but really what

00:01:19.290 --> 00:01:21.720 align:middle line:84%
happened with the use of
all of these techniques

00:01:21.720 --> 00:01:23.340 align:middle line:84%
is that there was
a lot of confusion

00:01:23.340 --> 00:01:26.400 align:middle line:84%
as to what was actually
going on at a global level

00:01:26.400 --> 00:01:28.660 align:middle line:90%
within cholera epidemiology.

00:01:28.660 --> 00:01:30.330 align:middle line:84%
And so what the whole
genome sequencing

00:01:30.330 --> 00:01:33.060 align:middle line:84%
has allowed us to do is actually
unify all of these things

00:01:33.060 --> 00:01:35.760 align:middle line:84%
into something that makes
sense, like a cohesive framework

00:01:35.760 --> 00:01:38.910 align:middle line:84%
for us to understand how cholera
is moving across the globe

00:01:38.910 --> 00:01:40.380 align:middle line:84%
and whether or
not epidemics, say

00:01:40.380 --> 00:01:42.780 align:middle line:84%
in Africa or Latin
America are actually

00:01:42.780 --> 00:01:44.700 align:middle line:90%
connected to one another.

00:01:44.700 --> 00:01:46.920 align:middle line:84%
OK, so in the
course, already we've

00:01:46.920 --> 00:01:51.000 align:middle line:84%
heard about John Snow how he
managed to track transmission

00:01:51.000 --> 00:01:55.980 align:middle line:84%
of cholera around London
using epidemiology,

00:01:55.980 --> 00:01:58.650 align:middle line:84%
why do we need these
tightly schemes

00:01:58.650 --> 00:02:02.610 align:middle line:84%
or genomics and those kind of
things you've just described.

00:02:02.610 --> 00:02:07.039 align:middle line:84%
No discussion of cholera can
be complete without John Snow.

00:02:07.039 --> 00:02:08.580 align:middle line:84%
And it was just
absolutely incredible

00:02:08.580 --> 00:02:11.039 align:middle line:84%
what he was able to do
in London at the time,

00:02:11.039 --> 00:02:13.660 align:middle line:90%
I think it was 1854.

00:02:13.660 --> 00:02:16.470 align:middle line:84%
But really what we're able to
do now with molecular techniques

00:02:16.470 --> 00:02:18.760 align:middle line:84%
and especially with
whole genome sequencing

00:02:18.760 --> 00:02:21.090 align:middle line:84%
is just have such a
better picture of what's

00:02:21.090 --> 00:02:22.470 align:middle line:90%
happening with cholera.

00:02:22.470 --> 00:02:25.710 align:middle line:84%
So in London, he was able to
track the individual cases

00:02:25.710 --> 00:02:28.110 align:middle line:84%
around the Broad Street
Pump, but now we're

00:02:28.110 --> 00:02:30.930 align:middle line:84%
looking at how cholera
affects individuals,

00:02:30.930 --> 00:02:33.630 align:middle line:84%
to households, to
communities, all the way

00:02:33.630 --> 00:02:36.750 align:middle line:84%
to how cholera is
spreading across a city.

00:02:36.750 --> 00:02:40.440 align:middle line:84%
So really being able to link up
who or where, perhaps cholera

00:02:40.440 --> 00:02:43.020 align:middle line:84%
is moving and then
even to a larger scale

00:02:43.020 --> 00:02:47.640 align:middle line:90%
across continents and globally.

00:02:47.640 --> 00:02:50.925 align:middle line:84%
And so how is your
research using genomics,

00:02:50.925 --> 00:02:55.230 align:middle line:84%
how has that helped you learn
about how cholera is spreading

00:02:55.230 --> 00:02:57.630 align:middle line:90%
over these large distances?

00:02:57.630 --> 00:02:59.760 align:middle line:84%
Yes, what we've
been able to do is

00:02:59.760 --> 00:03:03.840 align:middle line:84%
focus on the two regions
most affected by cholera,

00:03:03.840 --> 00:03:04.530 align:middle line:90%
historically.

00:03:04.530 --> 00:03:08.640 align:middle line:84%
So that's been Africa, which
is currently the continent that

00:03:08.640 --> 00:03:10.080 align:middle line:84%
has the highest
burden of disease

00:03:10.080 --> 00:03:12.090 align:middle line:90%
for cholera and Latin America.

00:03:12.090 --> 00:03:15.450 align:middle line:84%
And so what we've really done
is sequenced a lot of samples

00:03:15.450 --> 00:03:17.820 align:middle line:84%
from both of these
areas, including

00:03:17.820 --> 00:03:20.760 align:middle line:84%
with additional
samples from Asia

00:03:20.760 --> 00:03:23.170 align:middle line:84%
and really piecing together
the puzzle of how cholera

00:03:23.170 --> 00:03:24.970 align:middle line:90%
is moving across the globe.

00:03:24.970 --> 00:03:26.490 align:middle line:84%
So what we've been
able to show is

00:03:26.490 --> 00:03:29.520 align:middle line:84%
that cholera enters
into Africa at least

00:03:29.520 --> 00:03:33.180 align:middle line:84%
11 times since the
1970s, all from strains

00:03:33.180 --> 00:03:34.800 align:middle line:90%
originating in Asia.

00:03:34.800 --> 00:03:38.160 align:middle line:84%
And also in Latin America, we've
been able to show that again,

00:03:38.160 --> 00:03:40.080 align:middle line:84%
introductions of
pandemic strains

00:03:40.080 --> 00:03:42.360 align:middle line:84%
of cholera into
Latin America were

00:03:42.360 --> 00:03:46.060 align:middle line:84%
responsible for some of the
largest epidemics we've seen,

00:03:46.060 --> 00:03:50.790 align:middle line:84%
such as in Haiti in 2010,
and in Peru in 1991.

00:03:50.790 --> 00:03:56.250 align:middle line:84%
OK, so specifically how are
these importations happening,

00:03:56.250 --> 00:04:00.090 align:middle line:84%
is it via people
or is it via water?

00:04:00.090 --> 00:04:03.510 align:middle line:84%
Yeah, that's a great
question actually.

00:04:03.510 --> 00:04:06.270 align:middle line:84%
So we do believe that it's
through human-to-human

00:04:06.270 --> 00:04:08.130 align:middle line:90%
movement, primarily.

00:04:08.130 --> 00:04:10.560 align:middle line:84%
Some say that large
transport could

00:04:10.560 --> 00:04:13.650 align:middle line:84%
happen through the
releasing of ship water

00:04:13.650 --> 00:04:15.990 align:middle line:84%
into different ports,
but really this

00:04:15.990 --> 00:04:17.637 align:middle line:84%
is mediated all
by human movement.

00:04:17.637 --> 00:04:19.470 align:middle line:84%
Yeah, and you wouldn't
have been able to get

00:04:19.470 --> 00:04:22.740 align:middle line:84%
that from epidemiology
alone, you

00:04:22.740 --> 00:04:25.590 align:middle line:84%
need the typing
data to answer that.

00:04:25.590 --> 00:04:28.440 align:middle line:84%
Absolutely, so through
whole genome sequencing,

00:04:28.440 --> 00:04:31.170 align:middle line:84%
we were able to
use snips to draw

00:04:31.170 --> 00:04:35.460 align:middle line:84%
a really robust phylogeny's,
which allow us to then make

00:04:35.460 --> 00:04:38.070 align:middle line:84%
robust inferences
on how cholera has

00:04:38.070 --> 00:04:43.590 align:middle line:84%
moved throughout the globe
with really high resolution.

00:04:43.590 --> 00:04:44.790 align:middle line:90%
Thank you very much, Daryl.

00:04:44.790 --> 00:04:46.580 align:middle line:90%
Thanks Josie.

00:04:46.580 --> 00:04:49.750 align:middle line:90%