An analysis of sewer water has detected the virus as early as 15th of January in Barcelona. See for example (in Spanish) https://www.lavanguardia.com/local/barc

An analysis of sewer water has detected the virus as early as 15th of January in Barcelona. See for example (in Spanish) https://www.lavanguardia.com/local/barcelona/20200607/481654145204/detectados-restos-coronavirus-covid19-aguas-residuales-barcelona-enero.html https://www.lavanguardia.com/local/barcelona/20200607/481654...