Well if you go by what info is out there. Atm it all comes from China in dealing with the early stages of the outbreak. So take it with a lot of salt. Though most of it is from doctors that where silenced by the CCP.

In December human to human transfer was rampant in China. More to the end than at the start. At the start, Wuhan was really struggling as they (doctors) knew something was spreading and killing people. Doctors knew it was a type of coronavirus.

In was near the end of December when it was really out of control. Of course the CCP and the WHO did everything to keep it hidden from the world.

People were still traveling. But like I said the info is from China. But mainly from doctors that had to deal with it.