With so much news and media coverage people are struggling to understand the numbers at times and who can blame them?
Talk of "exponential growth", "doubling times" and "flattening the curve" are new terms to a lot of us.
Some people look at our current number of cases and deaths and say,
"What's the problem? More people die from flu each year."
Whilst that is true at the moment, it may not be true for much longer and we could rapidly reach a situation where more people die from COVID-19 than any other illness .
Perhaps a rather simple analogy is to consider someone breaking a leg.
Imagine you live in a town of around 50,000 people.
On any given night of the year 2 people in that town fall over and have to go to A&E with a broken leg.
The hospital is always able to cope with 2 cases of broken legs per night.
Very occasionally the break can be potentially fatal because the bone tore an artery as it broke but, with immediate and expert care, the situation can be salvaged.
Unfortunately a new and previously unknown way to break your leg is about to hit town.
There's a new trip hazard in town on every road and pavement but no-one can actually see it. You only know it's there after you've fallen over it and broken your leg. This new trip hazard likes crowded places in particular because it can get lots of people at once!
And it gets even worse...when one person falls over it makes 2 more invisible trip hazards appear all across town.
In just one night 100 people are going to break their leg, the next night it will be another 200, the night after that another 400, by the third night it is 800, by the fourth night it's 16,000 and by the fifth night it is 32,000 people. And the total number of cases is all these numbers added together. That's nearly all of the town's population, all with broken legs at virtually the same time.
The queue to be seen in A&E snakes halfway across the town, there is no way the hospital can cope with this number all at once.
Most people in the queue will be okay but some won't. The first few people in through the doors with very nasty breaks who need an operation and an intensive care bed will get them but the hospital will soon run out of resources for anybody else with a catastrophic break.
The only way to stop this happening is to stop people falling over the trip hazards, but you can't see them so you can't just remove them.
The one thing you can do is to ask people to stay indoors, away from the trip hazards.
At least then the hospital can cope with that initial group of people who have broken their leg.
Eventually you may have to let some people back into town knowing they may fall and break their leg but the hospital can still cope if they do.
By the end of the month the hospital may have dealt with the same number of people who broke their leg but the difference is they were spread over a whole month not just 5 nights.
And there is another benefit, whilst people are being careful and staying indoors scientists may come up with a way to get rid of the trip hazards altogether.
So, with COVID-19 the trip hazard is the virus, we can't see it but it's there.
Unchecked there is the potential for 80% of our population to become infected and within a very short period of time, just weeks...that's virtually the whole town with broken legs by day 5. This rapid doubling of numbers is exponential growth.
The only solution is to stay away from the trip hazards by staying at home and away from other people as much as possible, otherwise known as social distancing.
The same number of people may still break their leg in the end but over a month, not 5 nights. This is flattening the curve.
And whilst everybody is staying at home scientists may find a way to get rid of the trip hazard altogether, that's drugs or a vaccine.
Here's a link to an 8 minute YouTube video that explains this in a more scientific but very accessible way.
