The seroprevalence study by Hema-Quebec and the province’s public health institute tested the blood of 7,691 people between the ages of 18 and 69 who donated blood between May 25 and July 9.
When extrapolated to the rest of the population, the study estimated that some 124,800 adults contracted the virus since the pandemic began.
The Quebec government reported some 37,000 cases for the 20 to 69 age group in the same period.
The study revealed that the highest rates of infection were found in Montreal and Laval, with just over three per cent, while in most of the rest of the province the rate was much lower at 1.29 per cent.
Authorities will contact the donors who had COVID-19 antibodies to document their symptoms in order to estimate how many of them were asymptomatic.
© 2020 The Canadian Press