Milan Italy had Covid samples in their sewage from right around the first case was discovered in Wuhan, which happened shortly after an international sporting event with heavy Italian participation. The Military Games were done in late October.

https://pmc.ncbi.nlm.nih.gov/articles/PMC7428442/#%3A%7E%3Atext=In+Italy%2C+our+group+has%2Cet+al.%2C+2020).

The earliest dates back to 18 December 2019 in Milan

https://www.cdc.gov/museum/timeline/covid19.html

The very first thing on the timeline:

December 12, 2019

A cluster of patients in China’s Hubei Province, in the city of Wuhan, begin to experience the symptoms of an atypical pneumonia-like illness that does not respond well to standard treatments.

So regardless if China was able to stamp down and completely stop the pandemic in Wuhan immediately, it was too late. It was already abroad in Europe.