A large group of researchers came together for a study looking at the number of SARS-CoV-2 infections and mortality during the first wave of the pandemic across Canada.
Information from people living in different regions across Canada was collected. This included a finger prick blood sample which was self-collected at home by each individual and mailed to the researchers. In total 8,967 people mailed in blood samples and 19,994 completed the questionnaire. The overall presence of antibodies against SARS-CoV-2 was between 1.7% and 3.5%, with Ontario presenting the highest prevalence (2.4-3.9%), followed by Quebec (1.6-3.6%), and British Columbia and Yukon having the lowest (0.9-3.0%). From the questionnaires, researchers were able to determine that 31% of people who tested positive for antibodies had no symptoms at the time of infection.
An unfortunate finding was that the death rate in nursing homes was more than 70 times greater than among adults age 80 or older living outside of nursing homes. Further results suggest that 13-16% of Canadian nursing home residents had been infected by the time of the study.
The authors of this study conclude that given the low percentage of Canadians with antibodies against SARS-CoV-2, it is of the utmost importance that people get vaccinated, especially the elderly.
Tang X, Sharma A, Pasic M, Colwill K, Birnboim Ch, Nagelkerke Nico, Bogoch I, Schultz C, Newcombe L, Slater J, Rodriguez P, Huang G, Fu SH, Meh C, Wu ChN, Kaul R, Langlois MA, M E, Hollander A, Eliopoulos D, Aloi B, Lambe T, AbeK, Caldwell L, Barrios-Rodiles M, Fazel-Zarandi M, Weingust R, Wang J, Rathod B, Santhanam DR, Cho ER, Qu K, Jha S, Jha V, Suraweera W, Wen R, Sinha SR, Gingras AC, Chakraborty P, Slutsky AS, Jha P. COVID symptoms, seroprevalence, and mortality during the first wave of SARS-CoV-2 in Canada. Lancet. 2021 25 Jan. doi: 10.2139/ssrn.3752659.