Exponential Growth is Going Viral
Why the “unexpected spike” in Coronavirus cases is totally expected, and why you should take this seriously.
Imagine that, on a Sunday night, your city reports 5 cases of COVID-19.
A week later, on the following Sunday night, they report a total of 20 cases.
It is natural to think that the number of cases is growing by 15 per week. So, after four weeks, you would expect a total of 65 cases.
But what if they had also reported 10 cases halfway through the week?
Well, that would be a sign of exponential growth, with the number of cases doubling in the first half of the week (from 5 to 10), and doubling again in the second half of the week (from 10 to 20).
At that rate, after four weeks, we would expect a total of 1280 cases.
That’s 2000% worse than in the first case.
We know that the number of COVID-19 cases is growing exponentially.
I have seen stories in the news media that talk about “unexpected spikes” and “surprising jumps” in the number of COVID-19 cases.
None of this is unexpected or surprising. It’s exactly what we knew would happen, based on numbers coming out of China at the start of the year.
It explains why we’ve seen such drastic measures in Italy, with the entire country of 60 million people quarantined when there has “only” been around 9,000 cases of COVID-19. Because, left unchecked, those 9,000 cases would grow to 2,000,000 cases in the next four weeks. Remember, Italy had only 4 reported cases of COVID-19 as recently as February 20.
This is why we’ll see the same drastic measures in other countries soon. Including our own. But probably France, Spain and Germany first.
Governments know the consequences of unrestrained exponential growth, and they will do whatever it takes to slow it down. Please be aware of that.
Australia is only about four weeks behind Italy.
Luckily, we have the benefit of knowing what may happen here, which gives us a chance to be better prepared. So please try to slow community transmission of COVID-19 by adhering to some pretty simple rules:
- Wash your hands properly and regularly, especially when returning home and before eating.
- Don’t touch your eyes, nose or mouth.
- When greeting people, do not hug, kiss or shake hands.
- Self-isolate if you have a cough or a sore throat until you have spoken to your GP on the phone, and take their advice.
- Avoid all gatherings.
We must all do this to slow transmission rates, which will mean fewer people are sick at the same time, which will place less of a burden on health care. It’s easy and simple to do, and there really is no excuse.
Remember that people can infect others with COVID-19 up to 14 days before they start feeling unwell (but typically 5 to 7 days). The best thing we can all do is to behave as if everyone else already has it.
Finally, bear in mind that you may be quarantined, even if you and your family are not sick. This can happen suddenly, and many people in Italy were taken by surprise when it happened there. So make sure you always have a two week’s supply of food and medicine at home, by grabbing a few extra things each time you go shopping.
Stay healthy, and stay rational :)