That's a slightly different thing.
What you are looking at, is the measure of the tangent, on the graph of the total number of infected people.
ie. If there are 2,000 one day, and 2,600 the next, that number is (2,600/2,000) 1.3.
Italy in it's bad period, and the USA now, were running at 1.25-1.30, which is quite disastrous!
It means the number of confirmed cases is doubling every 2.5-3.0 days, and you can see, that very quickly gets out of control.
The number I'm talking about, is how many people (on average) each affected person passes the virus onto. The good countries have this number below 1, the bad countries are running at 3-5.
This can be approximated to the number you're talking by looking at it this way. From infection to being declared healthy, the virus has around a 16-20 day window, which includes a 6-8 incubation period. If each person with the virus is infecting 4 other people in their 18 days of having it that leads to the number you are refering to as being (1 + 4/18) 1.22, which is a pretty bad number, as far as containment is concerned.
The long incubation period is one of the things causing the biggest problem. People that are smitten, but not showing symptoms for 6-8 days, are the ones causing the biggest spread of the disease. Hence the need to restrict crowds, and people movement. Something Australia is slowly doing better, but unfortunately, slowly is the word for it.
