Analysis of Fatality Impact and Seroprevalence Surveys in a Community Sustaining a SARS-CoV-2 Superspreading Event

Abstract There is ongoing debate on the COVID-19 infection fatality rate (IFR) and the impact of COVID-19 on overall population mortality. Here, we addressed these issues in a community in Germany with a major superspreader event analyzing deaths over time as well as auditing death certificates in the community.18 deaths that occurred within the first 6 months of the pandemic in the community had a positive test for SARS-CoV-2. Six out of 18 SARS-CoV-2+ deaths had non-COVID-19 related causes of death (COD). Individuals with confirmed infection and COVID-19 COD typically died of respiratory failure (75%) and tended to have fewer reported comorbidities (p=0.029). Duration between first confirmed infection and death was negatively associated to COVID-19 being COD (p=0.04). Repeated seroprevalence essays on an original sample of 587 individuals in three visits showed modest increases in seroprevalence over time, and substantial seroreversion (30% [27/90] (95% CI: [20.5%; 39.5%])). IFR estimates accordingly varied depending on COVID-19 death attribution and seroprevalence caveats. Careful ascertainment and audit of COVID-19 deaths are important in understanding the impact of the pandemic.