Well, may be. Peer review required, but an interesting possibility.
Detectan el SARS-CoV-2 en aguas residuales recogidas en Barcelona el 12 marzo de 2019 (Universitit de Barcelona)
SARS-CoV-2 detected in Barcelona water study from March 2019
Covid-19 was in Spanish sewage as early as MARCH 2019, study claims
Coronavirus traces found in March 2019 sewage sample, Spanish study shows
Sentinel surveillance of SARS-CoV-2 in wastewater anticipates the occurrence of COVID-19 cases
December 2019, COVID-19 originated in Wuhan, China
Late January 2020, detected in France
February 25th first detected in Barcelona
Sewage in Barcelona
Frozen archival samples
January 15 to March 4, 2020 increasing levels
March 4 to May 4 2020, highest levels
Some uncharacterized influenza cases may have masked COVID-19 cases in the 2019-2020 season
Therefore January 2018 to December 2019 samples analysed
All samples tested negative for the presence of SARS-CoV-2 genomes with the exception of March 12, 2019,
The levels of SARS-CoV-2 were low but were positive
Indicates circulation of the virus in Barcelona long before the report of any COVID-19 case worldwide
A significant proportion of undiagnosed and asymptomatic carriers shed SARS- CoV-2 in stool
