From Reuters:
Spanish virologists have found traces of the novel coronavirus in a sample of Barcelona wastewater collected in March 2019, nine months before the COVID-19 disease was identified in China, the University of Barcelona said on Friday.
The discovery of virus genome presence so early in Spain, if confirmed, would imply the disease may have appeared much earlier than the scientific community thought. The University of Barcelona team, who had been testing wastewater since mid-April this year to identify potential new outbreaks, decided to also run tests on older samples.