Study reveals Italy had coronavirus since December.

A new study by Italian scientists has revealed that traces of the SARS-CoV-2 virus already existed in the wastewaters of Milan and Turin in December 2019.

This suggests that COVID-19 was already circulating in Northern Italy before China reported the first cases.

The study examined 40 wastewater samples collected from October 2019 to February 2020 and 24 control samples for which the sampling date (September 2018 – June 2019) allowed to safely exclude the presence of the virus.

The results, confirmed in the two different laboratories with two different methods, showed the presence of SARS-Cov-2 RNA in the samples taken in Milan and Turin on December 12, 2019, and in Bologna on January 29, 2020.

Water quality expert of the Department of Environment and Health of the Istituto Superiore di Sanità, Giuseppina La Rosa, conducted the study in collaboration with Elisabetta Suffredini of the Department of Food Safety, Nutrition and Veterinary Public Health.

La Rosa said in the same cities, positive samples were also found in the following months of January and February 2020, while the samples of October and November 2019, as well as all the control samples, gave negative results.

“This research can help understand the beginning of the circulation of the virus in Italy and provides information consistent with other results obtained from the retrospective analysis on samples of patients hospitalized in France, which identified a SARS-CoV-2 positive in a respiratory sample, therefore clinical, dating back to the end of December 2019, and to a recent Spanish work that found SARS-CoV-2 RNA in wastewater samples collected in mid-January in Barcelona, ​​about 40 days before the notification of the first autochthonous case,” the researchers said.

Also, Director of the Quality of Water and Health Department, Luca Lucentini said the result confirms the consolidated international evidence on the strategic function of monitoring the virus in samples taken regularly in the sewers and at the entrance to the treatment plants, as a tool capable of early identifying and monitoring the circulation of the virus in the various territories, supporting the fundamental information of integrated, microbiological and epidemiological surveillance.

“It should be noted that the discovery of the virus does not automatically imply that the main transmission chains that led to the development of the epidemic in our country originated from these first cases, but, in perspective, a surveillance network in the area may prove to be valuable to control the epidemic.

“Moving from research to surveillance, it will be essential to arrive at standardization of methods and sampling since the positivity of the samples is affected by many variables such as the sampling period, any meteorological precipitations, the emission of waste from industrial activities which may affect the results of activities to date conducted by different groups. We work to give the country a surveillance network together with Arpa and Ispra,” Lucentini said.

Based on the results of the pilot study, the researchers hope to be ready for surveillance on the whole national territory in the potentially most critical periods of next autumn.

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