Last month, French scientists said tests on samples showed a patient treated for suspected pneumonia near Paris in end-December actually had the coronavirus, while a study in Spain also found virus traces in waste water collected in mid-January in Barcelona, over a month before the first case was reported.
These findings are consistent with the estimates of chinese scientists who rely on the appearance of the virus in mid-December at a market in Wuhan selling the game, even though Beijing has recently suggested that the virus could arrive in China from overseas. The town became the first "red zone" in the country, followed by nine in both Lombardy and the neighboring Veneto region.
The novel coronavirus was already present in sewage systems of Milan and Turin in northern Italy as early as December, two months before the first Covid-19 cases were detected in the country, a new study showed, suggesting the virus was circulating much earlier than initially thought.
Italy was the first country in Europe to be hit hard by Covid-19 and strict restrictions were put in place.
Samples from October and November came back detrimental, showing that the virus experienced not nonetheless arrived, ISS h2o high-quality skilled Giuseppina La Rosa said.
The findings could help scientists understand how the virus began spreading in Italy, Ms La Rosa said.
Samples good for traces of the virus that triggers COVID-19 had been also located in sewage from Bologna, Milan and Turin in January and February 2020.
There have been 34,500 coronavirus related deaths in the country with several thousand still infected with the virus.
Given the large number of coronavirus cases that have little or no symptoms, waste water testing is seen as a potential way to signal the presence of the virus even before the first cases are clinically confirmed in areas untouched by the epidemic - or where it has ebbed.
The new ISS study "may contribute to shedding light on the first phase of the virus's circulation in Italy", La Rosa said.
Luca Lucentini, who leads the Italian health institute's department for Quality of Water and Health, said the Italian discovery does not mean "the main transmission chains that led to the development of the epidemic in [Italy] originated from these first cases".
The ISS said it had urged the health ministry to coordinate the collection of samples regularly in sewers and at the entrance to purification plants "as a tool to detect and monitor the circulation of the virus in different territories at an early stage".