Exponential contagion?

In recent weeks (February-March 2020) we are seeing the coronavirus epidemic spread in many western countries, both in Europe and in North America. The trend is very similar to what was seen in China a couple of months ago. At this point the cases grow exponentially. To understand what it means exponentially we can observe the growth of duckweed in an aquarium. It is an aquatic plant (not an algae) similar to a green lentil. Apart from sexually, it can reproduce asexually by bipartition. Consequently, a single lentil can be divided into 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096… Knowing that the aquarium will collapse in 30 days, what day would you say it will reach half its capacity? We could think that on the 15th, but as it grows exponentially it will reach half its capacity on the 29th, one day before the collapse, since the next day it will double the number and occupy the entire aquarium. The same can happen with the coronavirus epidemic. Now it seems unimportant, but tomorrow it may be catastrophic. Some models indicate that if social distancing is established we will reduce the number of infections and we will be able to reduce and finally stop the epidemic. But the response must be quick and forceful. We are in countdown.