The findings suggest the virus had spread to Europe fro China far earlier than first thought.
Italy’s first Covid-19 patient was officially identified on February 21st in a small town in the northern region of Lombardy.
But the study by the National Cancer Institute in Milan suggests the virus pay have been present in the region months earlier.
Reuters reports that Italian researchers’ found that 11.6% of 959 healthy volunteers enrolled in a lung cancer screening trial between September 2019 and March 2020 had developed coronavirus antibodies well before the first Covid-19 patient was identified.
A further SARS-CoV-2 antibodies test carried out by the University of Siena showed that four cases dating back to the first week of October were positive for antibodies, meaning they had first become infected in September, Giovanni Apolone, a co-author of the study, told Reuters.
“This is the main finding: people with no symptoms not only were positive after the serological tests but also had antibodies able to kill the virus,” Apolone said.
“It means that the new coronavirus can circulate among the population for a long time and with a low rate of lethality, not because it is disappearing, only to surge again,” he told the news agency.
Italian researchers told Reuters in March that they reported a higher than usual number of cases of severe pneumonia and flu in Lombardy in the last quarter of 2019 in a sign that the new coronavirus might have circulated earlier than thought.