//Virus in Barcelona, March 2019

Virus in Barcelona, March 2019

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)

https://www.ub.edu/web/ub/es/menu_eines/noticies/2020/06/042.html

SARS-CoV-2 detected in Barcelona water study from March 2019

https://www.catalannews.com/society-science/item/sars-cov-2-detected-in-barcelona-water-study-from-march-2019

Covid-19 was in Spanish sewage as early as MARCH 2019, study claims

https://www.rt.com/news/493085-covid-spain-march-2019-sewage/

Coronavirus traces found in March 2019 sewage sample, Spanish study shows

https://www.reuters.com/article/us-health-coronavirus-spain-science/coronavirus-traces-found-in-march-2019-sewage-sample-spanish-study-shows-idUSKBN23X2HQ

Sentinel surveillance of SARS-CoV-2 in wastewater anticipates the occurrence of COVID-19 cases

https://www.medrxiv.org/content/10.1101/2020.06.13.20129627v1.full.pdf

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