Daily US Times: Italian scientists say waste water from two cities contained coronavirus traces in December last year, which is long before the country’s first confirmed cases.
The National Institute of Health (ISS) said water from Turin and Milan showed genetic virus traces on 18 December.
It adds to evidence from other countries that the virus may have been circulating much earlier than thought.
Officials in China confirmed the first coronavirus cases at the end of December. Italy’s first case was in mid-February.
French scientists said in May that tests on samples showed a patient treated for suspected pneumonia near Paris on 27 December actually had the coronavirus.
A patient who has treated in a hospital near Paris on 27 December last year for suspected pneumonia actually had the coronavirus, his doctor has said. This is now considered the first known case of coronaviurs in the country.
Meanwhile, a study in Spain found virus traces in waste water collected in mid-January in Barcelona. It was 40 days before the first local coronavirus case was discovered.
ISS scientists examined 40 sewage samples collected from wastewater treatment plants in northern Italy between last October and February for their study.
ISS water quality expert Giuseppina La Rosa said, samples from October and November came back negative, showing that the virus had not yet arrived. Waste water from Bologna began showing traces of the virus in January this year.
Ms La Rosa said, the findings could help scientists understand how the virus began spreading in Italy.
She said, however, the research did not “automatically imply that the main transmission chains that led to the development of the epidemic in our country originated from these very first cases”.
Italy – one of Europe’s worst hit countries- first known non-imported virus case was a patient in the town of Codogno in the Lombardy region. On February 21, the town was closed off and declared a “red zone”. Nine other towns in Lombardy and neighbouring Veneto followed and the entire country went into lockdown in early March.
The ISS said the results confirmed the “strategic importance” of sewage water as an early detection tool because it can signal the virus’s presence before cases are clinically confirmed. The technique is currently used by many countries.
The institute says it aims to begin a pilot project monitoring waste water at tourist resorts in July with a view to setting up a nationwide waste water monitoring network later this year.
A tally from Johns Hopkins University shows nearly 35,000 people have died with Covid-19 in Italy.
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