1. Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection Fatality Rate Among Elderly Danes:A Cross-sectional Study on Retired Blood Donors
- Author
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Nanna Lond Skov Frisk, Kathrine Agergård Kaspersen, Janna Nissen, Christian Erikstrup, Klaus Rostgaard, Lise Wegner Thørner, Birgitte Grum-Schwensen, Jens Kjærgaard Boldsen, Susanne Gjørup Sækmose, Khoa Manh Dinh, Isabella Worlewenut Paulsen, Margit Hørup Larsen, Thorsten Brodersen, Lasse S Vestergaard, Robert Skov, Maria Didriksen, Henrik Ullum, Kåre Mølbak, Ole Birger Vestager Pedersen, Michael Schwinn, Erik Sørensen, Joseph Dowsett, and Henrik Hjalgrim
- Subjects
0301 basic medicine ,Microbiology (medical) ,medicine.medical_specialty ,infection fatality rate ,Cross-sectional study ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Denmark ,Population ,Blood Donors ,SARS-CoV-2 seroprevalence ,Antibodies, Viral ,Danish ,03 medical and health sciences ,0302 clinical medicine ,Seroepidemiologic Studies ,Epidemiology ,Case fatality rate ,Major Article ,medicine ,Seroprevalence ,Humans ,030212 general & internal medicine ,education ,Aged ,education.field_of_study ,business.industry ,SARS-CoV-2 ,SARS-Cov-2 antibody test ,SEROPREVALENCE ,COVID-19 ,Confidence interval ,language.human_language ,AcademicSubjects/MED00290 ,030104 developmental biology ,Infectious Diseases ,Cross-Sectional Studies ,ANTIBODIES ,language ,epidemiology ,business ,Demography - Abstract
Background Although the vast majority of individuals succumbing to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are elderly, infection fatality rate (IFR) estimates for the age group ≥70 years are still scarce. To this end, we assessed SARS-CoV-2 seroprevalence among retired blood donors and combined it with national coronavirus disease 2019 (COVID-19) survey data to provide reliable population-based IFR estimates for this age group. Methods We identified 60 926 retired blood donors aged ≥70 years in the rosters of 3 regionwide Danish blood banks and invited them to fill in a questionnaire on COVID-19–related symptoms and behaviors. Among 24 861 (40.8%) responders, we invited a random sample of 3200 individuals for blood testing. Overall, 1201 (37.5%) individuals were tested for SARS-CoV-2 antibodies (Wantai) and compared with 1110 active blood donors aged 17–69 years. Seroprevalence 95% confidence intervals (CIs) were adjusted for assay sensitivity and specificity. Results Among retired (aged ≥70 years) and active (aged 17–69 years) blood donors, adjusted seroprevalences were 1.4% (95% CI, .3–2.5%) and 2.5% (95% CI, 1.3–3.8%), respectively. Using available population data on COVID-19–related fatalities, IFRs for patients aged ≥70 years and for 17–69 years were estimated at 5.4% (95% CI, 2.7–6.4%) and .083% (95% CI, .054–.18%), respectively. Only 52.4% of SARS-CoV-2–seropositive retired blood donors reported having been sick since the start of the pandemic. Conclusions COVID-19 IFR in the age group >69 years is estimated to be 65 times the IFR for people aged 18–69 years.
- Published
- 2021
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