Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection Fatality Rate Among Elderly Danes: A Cross-sectional Study on Retired Blood Donors. (26th October 2020)

• Record Type: Journal Article
• Authors: Pedersen, Ole Birger; Nissen, Janna; Dinh, Khoa Manh; Schwinn, Michael; Kaspersen, Kathrine Agergård; Boldsen, Jens Kjærgaard; Didriksen, Maria; Dowsett, Joseph; Sørensen, Erik; Thørner, Lise Wegner; Larsen, Margit Anita Hørup; Grum-Schwensen, Birgitte; Sækmose, Susanne; Paulsen, Isabella Worlewenut; Frisk, Nanna Lond Skov; Brodersen, Thorsten; Vestergaard, Lasse Skafte; Rostgaard, Klaus; Mølbak, Kåre; Skov, Robert Leo; Erikstrup, Christian; Ullum, Henrik; Hjalgrim, Henrik
• Is Part Of: Clinical infectious diseases. Volume 73:Number 9(2021)
• Page Start: e2962
• Page End: e2969
• Publication Date: 2020-10-26
• Subjects: COVID-19 -- infection fatality rate -- epidemiology -- SARS-Cov-2 antibody test -- SARS-CoV-2 seroprevalence; Communicable diseases -- Periodicals; 616.905
• DOI: 10.1093/cid/ciaa1627
• Languages: English
• ISSNs: 1058-4838

Abstract

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. Abstract : COVID-19 infection fatality rate was 5.4% and 0.083% in the age group >69 years and 17–69 years, respectively. SARS-CoV-2 seropositives were generally less inclined to follow official recommendations against spread of disease. Only 52.4% reported to have been sick from COVID-19.