This is a summary, written by members of the CITF Secretariat, of:

Lewin, A., Therrien, R., De Serres, G., Grégoire, Y., Perreault, J., Drouin, M., Fournier, M. J., Tremblay, T., Beaudoin, J., Beaudoin-Bussières, G., Prévost, J., Gendron-Lepage, G., Finzi, A., Bernier, F., Bazin, R., Germain, M., & Delage, G. (2021). SARS-CoV-2 seroprevalence among blood donors in Québec, and analysis of symptoms associated with seropositivity: a nested case-control study. Canadian journal of public health, Revue canadienne de santé publique, 112(4), 576–586.

The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.

A study led by Héma-Québec, the provincial blood collection agency, supported by the CITF and featuring CITF-funded researcher, Dr. Andrés Finzi, showed that 2.23% of blood donors were seropositive for SARS-CoV-2 between May 25 and July 9, 2020: about four times higher than the number of PCR-confirmed COVID-19 cases during the same period. In addition, questionnaire data revealed that approximately 50-66% of those who were seropositive were asymptomatic. Of those who reported having symptoms, the most common were fever/chills and loss of taste/smell. Blood samples were collected from 7,691 adult blood donors during the first wave of the pandemic in Quebec, the hardest hit province at that time, and analyzed for the presence of antibodies against SARS-CoV-2.