An open source peer reviewed study in Italy states that anti-bodies for covid-19 were detected in blood samples in Italy as early as September 2019!
https://journals.sagepub.com/doi/10.1177/0300891620974755?url ver=Z39.88-2003&rfr id=ori%3Arid%3Acrossref.org&rfr dat=cr pub++0pubmed&
Blood samples taken from 959 asymptomatic patients as part of a nationwide lung cancer screening program subsequently showed contained 111 (11.6%) antibodies to SARs Cov2 in the receptor binding domain which means they were definitely infected with Covid-19 over 4 months BEFORE Italy s first official cases of Covid-19, 2 chinese tourists on the 30th of January 2020 who had traveled form China to Rome. Whilst the first italian confirmed case of community spread of Covid-19 was on the 20th of Feb 2020 in Lombardy.