it's the year 2020 through the decades

we've increased our ability to organize

and change the world around us

[Applause]

advances in food production mean that

even as the world's population explodes

nobody should be going hungry

[Music]

modern medicine means most of us are

living longer healthier lives

and yet all the signs couldn't protect

us from a pandemic

but a closer look will tell us it's

because of our way of life that we're

vulnerable to new infectious diseases

not in spite of it and it's that same

way

of life that is setting us up for

further outbreaks

[Music]

we're so advanced we're so clever and

yet a

tiny virus can cause havoc around the

world

dws nina reddy takes a look at just how

we got here

covid 19 is an unprecedented global

health emergency

in many ways but the emergence of the

new disease

is also part of an alarming pattern

scientists say the number of new

infectious diseases in humans like

sars mers and covid19 has risen

dramatically over the last decades

a study showed that the number of

emerging infectious diseases in humans

almost quadrupled between 1940 and 2000.

an especially large spike in the 1980s

was attributed to diseases linked to the

hiv aids epidemic

and there's not just more types of

diseases the number of

outbreaks is rising too in fact the

number of outbreaks of all diseases

has roughly tripled since 1980. if you

sat down systematically

and counted up the

number of new infections that we have

identified it has increased we continue

to see

increasing infectious disease outbreaks

caused by bacteria or viruses that we

did not previously know

we have created the circumstances on

earth

that make it likely that this will

continue

so what's causing the rise of new

infectious diseases in our world today

and how do humans contribute the reasons

are vary but they're all intertwined

so let's take a look at some of the main

ones population

size there are more and more of us

on the planet when the spanish flu broke

out in 1918

there were around 1.8 billion people

across the globe

by the 1970s there were already 3.7

billion of us

in the past 50 years the global

population has more than

doubled and it's projected to grow even

further by 2050.

more people also means we live closer

together

and in some parts of the world that

means very close

this makes human to human transmission

of viruses easier

and the sheer amount of people makes it

more likely that one of us will catch a

virus

as we spread out on the planet human

interference with nature

more people have led to an increased

need for land and production capacity

the result a rise in deforestation and

land use change worldwide

for industrial agriculture logging and

mining or urbanization

this means humans come into increased

contact with wild animals

that may carry infectious diseases also

natural habitats are destroyed

driving animals into suburban areas

where they encounter people and

livestock

it is often the changes in the landscape

driven by increases in population

that has brought us into closer contact

with the viruses that were already

present in animals or present in the

environment

but we now have created a much larger

interface and are much more likely to

come into contact with them

studies have linked deforestation to

increases in malaria infections

in the amazon region and to the outbreak

of ebola

in west africa but the risks of human

interference with nature

don't stop there human-driven climate

change

can also contribute to new disease

outbreaks

events like droughts can force wild

animals to move away from their habitats

and disease-carrying insects like

mosquitoes or ticks

living in warmer areas are more likely

to spread to new regions

as global temperatures rise mass

consumption of animal products

more people also means we need more food

and intensified farming

as average global wealth has increased

so has the consumption of

animal products though numbers vary by

country

the average meat consumption per capita

has risen from 23 kilograms per year in

1961

to nearly double that some 50 years

later

higher demand means more mass animal

farming

which increasingly looks like this

animals are squeezed together over long

periods of time

in an extremely small space as farming

intensifies

so does human to animal contact and

transporting these animals

internationally

elevates the risk of a virus spreading

around the world

global mobility when it comes to

spreading a virus

it's not only goods moving across

borders it's our own movement in a

globalized world

that plays a central role covid19

is evidence of this a virus which spread

across the globe in a matter of weeks

causing a pandemic and infecting

millions of people worldwide

in the past century growing average

wealth and cheaper flights have allowed

us to travel more

faster and easier than ever before in

2018

over 4 billion passengers boarded

flights worldwide

half a century earlier in 1970 it was

only around 310 million

while at the beginning of the century

1900 well

the first plane hadn't even lifted off

yet this is not new

in history i mean people traveling along

the silk road

in past centuries and ships that carried

passengers that had cholera but the

scale

and magnitude of travel today at least

until the past

few months is really unmatched in

history

and today one can reach virtually

any part of the earth within the

incubation period of many infectious

diseases

but it's not all bad news while the

number of diseases is increasing

we are also better equipped to respond

to them

in the past century researchers have

developed better tools to detect

research and develop treatments and

vaccines for diseases

making many of them far less deadly like

hiv or virtually eradicating them

like smallpox when i think of hiv aids i

remember when the first cases

we were seen in the hospital and

initially it was a death sentence

over the years extremely effective

treatment became available

and it is now um treated like a chronic

disease

so on the one hand things are getting

better but covert 19 is proof that it is

far from over

in a world as it looks today there is no

way around new diseases emerging

we will have to learn to fight them and

the coronavirus pandemic

is teaching us how i think covert 19 has

had

a number of lessons already one we need

a strong

public health system we also need to

continue investment in basic science and

in vaccine development

even in the absence of an epidemic and

we need better surveillance

systems that integrate information about

humans

and animals i am optimistic that we

will be able to provide interventions

but it will take time

and professor freedom and weber is

director and chair of the institute for

virology

at the justice league university in

geesen where he focuses on

veterinary medicine first of all it's

good to have you with us

and let me start by picking up on that

last point that was mentioned in our

report just now where it said

we need better surveillance systems that

integrate information about humans and

animals

now can you give us an example where

such a surveillance system

already exists and discovered a disease

and prevented it from spreading

i could give you a very well-known

example actually there's

it doesn't entirely prevent the spread

but certainly

like um have has prevented a larger

outbreak that is influenza and this is

done every year

every year the influenza strains in

china are being surveyed

by the who and this gives us a chance to

predict

what kind of influenza strains are

coming over

to the other countries and this gives us

buys us about half a year's time to

manufacture

tailor-made vaccines this would not be

possible without this early warning

system

so that's an example from human medicine

if you want yeah it just

it seems to be working perfectly well

what needs to be improved in order

to get a better idea about the health of

animals and humans

well all over i think it is impo

important to test

like help everything if you want yeah i

mean it depends on what do we want to

look at is

that the known viruses for these we can

test very in a targeted manner

or for unknown ones for this is a bit

more complicated for this we need to

wait for a disease to come up if you

want

so in this report we also heard about

the role of biodiversity and how

humans interfere with the world how big

a role does

biodiversity play for our health

a very big role of course

and for viruses it's a bit complicated

because if you have a

huge repertoire of different animal

species that means you have a huge

repertoire of different viruses

and some of them have the capability to

jump into humans others not but the more

different species you have the higher

the chances are

but once you have a virus which bets

very well

either in different animals and humans

or just in different animals and it

mutates over

then it's better to have a smaller

variety

of species but many different

individuals of it

so it can go through like through

monoculture

and we're obviously doing an awful lot

in order to to lower the amount of

biodiversity around us now renowned

per primatologist jane goodall actually

blames kobet 19 on our

exploitation of the natural world she

said that we brought this on ourselves

does she have a point there

she definitely has a point i mean this

is a um

simply about the chances of getting into

contact with exotic

viruses and they come from exotic

animals and when do we

meet exotic animals so this is for

example on these wet markets in china

or when there's a bush meat market in

africa

but even it doesn't mean to need to be

necessarily exotic because

diseases like influenza for example they

come from pigs and and birds

which means birds means chicken and

ducks or from cattle we have caught

measles once so it's always the same

when you come in close contact to

animals

you may have never met before then

charges are high

you get a virus from them all right so

we'd be well advised to change our

behavior just a little bit

professor weber from the institute of

virology in giessen thank you so much

for your time

you're welcome bye-bye miss jones

and talking of time it's now time for

your questions here's our science

correspondent

derek williams

are all the new infections due to social

distancing norm violations

or in spite of following them

i'd say both some people are of course

going to be infected with the virus as a

direct result of ignoring lockdown rules

there have been a few high profile cases

where that's happened recently like the

belgian prince

who came down with covet 19 after going

to a party

in spain but but sticking strictly to

social distancing rules like staying two

meters away from others

doesn't mean you're completely protected

among other things

we're still learning about how long

exactly the virus

stays airborne the latest indicator is

that tiny

drops aerosols that that could

potentially

carry the virus can remain suspended in

the air in enclosed

spaces for for over 10 minutes so

although there's lots of evidence that

social distancing rules

lower your risk sometimes significantly

nobody is saying they provide any

iron-clad guarantees

do i have to clean packaging on products

before storing them at home

i get asked this question all the time

because we all have to eat

right and since you don't know who's

handled those groceries you just picked

up it's easy to worry about

how much of a danger they might pose

but although soros cove 2 appears to

remain

viable on some surfaces for up to 72

hours

most experts at this point don't

recommend

that you disinfect packaging because it

appears to pose

quite a low risk the primary way the

virus spreads

seems to be through the air rather than

through direct physical contact

with objects that might bear the

pathogen

but of course it's still a good idea to

to wash your hands

thoroughly after shopping and putting

away your groceries

what about the fatal effects of

long-term unemployment

there's widespread acceptance of the

idea that that long-term

unemployment affects both your mental

and your

and your physical health that people who

are out of work for longer periods

are are more anxious or depressed than

the average

and are at higher risk of strokes

and cardiovascular disease or or other

serious illnesses but

i found it surprisingly difficult to

track down

recent studies on the topic that that

tried to quantify

the health effects of unemployment

across the board

one that was conducted in sweden last

year

determined in a survey involving around

a thousand adults that

that taking many different health

factors into account

unemployment hits people quite hard both

emotionally

and physically and if it does that in a

place

like sweden which has quite an extensive

social safety net the impact is likely

to be felt even more

in other countries

you