Here's the W H O earlier.

We're deeply concerned both by the alarming levels, off spread and severity and by the alarming levels off in action.

We have therefore met the assessment that coverted 19 can be characterized as a pandemic.

This is the first panda me caused by a coronavirus, and we have never before seen a pandemic that can be controlled at the same time.

Well, you see coverage off this announcement on the BBC news website.

In our coverage, we describe a pandemic is meaning a disease that's spreading in multiple countries around the world at the same time.

But the question here is, what is this changing categorization actually mean?

Well, is the BBC's Philip Iraq's be wh says this will not change anything that they're saying it will change very little that countries are actually doing because they've already been having very close relationships with many of these countries over weeks and weeks now, in telling them what to do.

Eso this This is really it's not surprising that this word is now being being used mega 1,000,000 a figurative way.

It won't change very much on the ground.

This graphic from Johns Hopkins grown a virus research center, shows the spread of the disease across the world.

The bigger the red circle, the bigger the outbreak.

We know there are now more than 120,000 cases globally in 118 countries on more than 4300 people have died on.

One consequence of this pandemic is pressure on health care systems.

For example, in Iran, on Italy, this is really putting.

Italy's health care system, which is one of the best, most well developed in Europe, is putting it under a great deal of strain.

We've seen footage from some hospitals where intensive care units have been set up in hospital corridors and their fears that if this virus spreads significantly to the south, where the health care is not as well developed, that could have a very serious effect.

Thier Corona viruses rapidly claiming lives across the country and not just the elderly young medics in their twenties.

With thousands of confirmed cases, the hospitals can't cope, nor can the staff.

This is one off several makeshift hospitals that are being set up in the city off home the epicenter off the outbreak.

Of course, in Iran and Italy.

As the number of cases rise, so does the pressure on health care.

And that's a concern that's widely shared.

His Angela Merkel, speaking today, was when the viruses out there, the population has no immunity and no therapy exists.

Then 60 to 70% of the population will be infected as long as this situation continues to exist.

My 60 to 70% of the German population is around 50 million people.

And if that would have happened even if only a small proportion of those people needed hospital care, that would still swamp the German health system.

And earlier this week, Mrs Merkel outlined the best way to avoid that kind of scenario.

Is that really sums Demeter Kingdoms vehicles?

The fact?

What site?

In a situation like this, the most effective means against the virus is to gain time to reduce the pressure on doctors and hospitals.

If a lot of people were to become ill within a very short space of time, the most effective tool against the virus is to slow it down on to stretch out its development for lungs.

I think this idea is often called flattening the curve.

This is what it looks like in a graphic for Miss from The New York Times.

Adapted from a report from the Center for Disease Control.

The red area here is what would happen with surge of infections.

If you have no proper measures in place and you can see it goes across this dotted line, which signifies health care capacity, it's way above healthcare capacity.

If a country, though, concedes early on, there are gonna be large numbers of cases and focuses on slowing the spread, the outbreak takes longer to play out.

But you never reached that point where a health care system can't cope, his one senior U.

S.

Official and there are a number of things that one can do in order to blunt it.

If you look at the curves of outbreaks, you know, they go big peaks and they come down.

What we need to do is flatten that down.

That would have less people infected that would ultimately have less deaths.

You do that by trying interfere with the natural flow of the outbreak.

The man who popularized this graph is a population and health analysts called Drew Harris.

He was initially using this to teach his classes, but it's since gone viral after it was linked to this particular virus.

And as Drew points out in this tweet, you've gotta bear in mind that what is graph represents is the difference between finding an intensive care unit bed and events later.

Well being treated in the parking lot tents.

And I spoke to Drew earlier from Philadelphia on what governments can do to flatten the curve.

Well, they certainly can begin to isolated.

Treating sick to quarantine the corn time accordion the people were, they contacted closed schools and prevent the spread of disease down through the Children and encourage social distance in keeping people apart both in time and place.

And that means maybe folks stagger work hours so they don't go to work at the same time.

Or you make sure that when people are in the same place that they're not as close to each other and the course, we need to protect yourself individually by make sure you wash your hands and using hand sanitizers.

But there's evidently some discussion about when best to bring those measures in the UK for example, is acknowledging they may come, but they're not coming yet.

Yes, the challenge and starting to soon is that people become complacent.

They say, Well, what's the point?

There's no disease spreading.

But if you wait too late until a glorious taking hold, then you are dealing with situation like they happen Italy.

So that timing is gonna be absolutely critical.

And generally the experts are going to tell you, is one of cases start to show up, spreading within the community from person to person?

The challenge we have with this particular virus that seems that people are contagious even before they show symptoms.

So they don't know that their efforts for spreading the disease until maybe they have done it in this predatory people isn't there 1/3 scenario we could add to your graph, which is where governments do take the relevant measures.

But still, the number of cases take health care systems beyond their capacity.

Well, it's all about flat in the current may.

We don't do it is completely is necessary, but anything we can do to lower that peak and prevent folks from everyone from getting sick at that same moment in time it's that spread the mouse that gets sick later is going to be an improvement and hopefully reserves some of that capacity for the people who really need it.

And one final question.

Is there a choice between trying to contain this virus and trying to flatten the curve?

Can those two things actually be working against each other?

I think at this point, payment this is not goingto happen is though this disease is going to spread.

Every expert will tell you that the pandemic of this night is gonna eventually move itself into every community in the world.