CDC chief said 50% of cases are very mild or have no symptoms...ie...not being counted. That seems fair considering 10% of the population gets influenza.. 100 million in china have likely had the chance to get the virus...10% of that would be 10 million infected...we have only had 80k cases which have caused symptoms...80% of these are mildish, 10% severe, 5% critical, 2% lead to deaths. Respiratory and cardiovascular health seems to be a key determinant of survival. Respiratory health in china is abysmal, they might have a million people die from pollution related illnesses in a year. The virus has been transferred throughout eastern china during the new year celebrations so I don't buy that it hasn't expanded...I believe from outbreaks in Western nations that it is easily fought off by the young and middle aged and often undetected until it hits an elderly person with poor health.
I don't know where you are getting your numbers, but they don't appear to be correct.
Of the 35,682 cases where the virus has run its course..
32,878 (92%) recovered and were Discharged. 2,804 (8%) resulted in Deaths.
Of the 46,501 Currently Infected patients..
38,032 (82%) are in Mild Condition.
8,469 (18%) Serious or Critical.
The total that have died so far after contracting the virus represents a mortality rate of 3.4%.
Again, the mortality rate of those where the virus has run its course (8%) are the more important numbers, because there are large numbers of people where the virus is newly diagnosed and hasn't run its course.
I would say that the U.S. will be better prepared to respond to the virus, and will lower mortality rates, but no one has existing antibodies, regardless of the country, so we need to take this very seriously. Especially since it's incubation period is so long.