Coronavirus traces have been discovered in wastewater collected from Italy in December 2019, weeks before China reported its first cases.
Scientists in Italy have found traces of the new coronavirus in wastewater collected from Milan and Turin in December 2019 – suggesting COVID-19 was already circulating in northern Italy before China reported the first cases.
The Italian National Institute of Health looked at 40 sewage samples collected from wastewater treatment plants in northern Italy between October 2019 and February 2020.
An analysis released on Thursday said samples taken in Milan and Turin on December 18 showed the presence of the SARS-Cov-2 virus.
“This research may help us understand the beginning of virus circulation in Italy,” said Giuseppina La Rosa, an expert in environmental wastewater at the Italian National Institute of Health who co-led the research.
A spokeswoman for the institute said the full data and study would be published next week.
Research in the Netherlands, France, Australia and elsewhere has found signs that the virus that causes COVID-19 can be detected in sewage, and many countries are beginning to sample wastewater to track the disease.
Scientists said the detection of traces of the virus before the end of 2019 was consistent with evidence in other countries that COVID-19 may have been circulating before China reported the first cases on December 31.
Noel McCarthy, an expert in population evidence and technologies at Britain’s Warwick Medical School, said the detection of SARS-Cov-2 genetic material in Italian wastewater in December was “reliable evidence of cases of COVID-19 being present there at that time”.
Rowland Kao, an epidemiology and data professor at Scotland’s Edinburgh University, agreed it was plausible the disease could have circulating then, but added:
“(This finding) does not on its own, however, tell us if that early detection was the source of the very large epidemic in Italy, or if that was due to a later introduction into the country.”
A study in May by French scientists found that a man was infected with COVID-19 as early as December 27, nearly a month before France confirmed its first cases.
Source: News.com.au (excerpt)