In a peer reviewed paper published 2021 by University of Kent and the Czech Academy of Sciences, the scientists estimates that the SARS-CoV-2 virus first appeared between early October to mid-November 2019, and noted that “significant changes in hospital and search engine traffic in Wuhan” suggest it may have been present as early as August to October, 2019.
The study concluded that November 17, 2019, is the most likely date for the virus’ emerged in China and adds that it had probably already spread globally by January 2020—before China began locking down the city of Wuhan. [2]
Another study led by Francois Balloux estimate from phylogenetic assessment that October 6, 2019 could be the pandemic start date. [1]
Spanish virologists were reported to have found traces of the virus from Barcelona waste water samples collected March 12, 2019 [unconfirmed].