I ran the numbers using beginning with 41 infected people, and each one of them able to infect 3 other people. At day 12 it came to 44 million people infected. That seems really high, so I either did the math wrong or made some wrong assumptions. For example, not everyone comes in contact with a bunch of different people every day.
But - 90,000 dead out of 44 million is a mortality rate of 0.2%. Last years mortality rate of flu in the USA was estimated at 0.3% - with 90,000 dead from the flu. Although the first thing I thought when I heard the Asian gal talking about 90,000 - “Hmm - I wonder if they just pulled that number out of wikipedia?”
What was your assumption for the time it takes each person (actually the virus they are carrying) to become infectious?
With most viruses, as I understand it, one is not infectious until the incubation period has run it’s course and symptoms present - however mild they might be at the beginning. I suspect this is not the precise “one phase ends, the next begins” that it is often made out to be, and that one’s own infectiousness “ramps up”, perhaps being at a low level before symptoms are detectable.
Then the incubation period itself can vary greatly from one individual to another. I’ve read it can be anywhere from 1 to 14 days. What is “typical” for 2019-nCoV I don’t know, and I don’t even know if it could determined accurately this early on in a setting where many potential contacts might exist.
Additionally, some reports indicate 2019-nCoV can be infectious during the incubation period. I very much doubt this would be likely in the first half of the incubation period, assuming a single time of exposure. But this could be related to that “ramp up” of infectiousness I was speculating about, or perhaps for some victims there is an extended period of very low level symptoms coupled with a significant degree of infectiousness.
(Several times in the past I have thought I had a cold starting, then seem to “stall” (only mild symptoms), then it’d seem to almost disappear for a few days, and just about the time I thought, “yeah, I have this beat”, it’d roar back as a full fledged head cold and put me in bed for a day or two. I was probably infectious the whole time, but, HOW infectious each day? Hmmm.)
All that makes for quite complicated & tedious “predicting” or computation. However, one can crunch it down into a sort of average: Let’s say that for 2019-nCoV, each person infected becomes infectious in 4 days, and infects 3 other people, all on that 4th day, and thereafter is out of the picture.
Day 0 = 41 infected.
Day 4 = 123 infected.
Day 8 = 369 infected.
Day 12 = 1107 infected.
Day 16 = 3321 infected.
And so on.
That is “way simplistic”, but gives some idea of the progress of the disease.