The coronavirus was present in Milan and Turin’s sewage systems as early as December, two months before the first Covid-19 cases were detected in Italy, a new study shows.
“Traces of SARS-Cov-2 have been found in samples of waste water taken in Milan and Turin on Dec. 18 and in Bologna on Jan. 29,” said Giuseppina La Rosa, who led the research for a coming study from the country’s ISS National Health Institute. “More traces were detected in other test samples through January and February.”
The report is part of a regular round of testing on environmental virology that’s been carried out since 2007 by the ISS’s environment and health department. Overall, 40 samples were analyzed from October 2019 to February 2020 with an additional 24 from September 2018 through June 2019 used as controls.
The new ISS study “may contribute to shedding light on the first phase of the virus’s circulation in Italy,” La Rosa said. The results are consistent with similar tests carried out on waste water in Barcelona and with clinical tests on patients hospitalized in France, which showed biological traces of the virus as early as last December.
