Do not neglect SARS-CoV-2 hospitalization and fatality risks in the middle-aged adult population

Objectives: This study aimed at estimating the SARS-CoV-2 infection hospitalization (IHR) and infection fatality ratios (IFR) in France. Patients and methods: A serosurvey was conducted in 9782 subjects from the two French regions with the highest incidence of COVID-19 during the first wave of the pandemic and coupled with surveillance data. Results: IHR and IFR were 2.7% and 0.49% overall. Both were higher in men and increased exponentially with age. The relative risks of hospitalization and death were 2.1 (95% CI: 1.9-2.3) and 3.8 (2.4-4.2) per 10-year increase, meaning that IHR and IFR approximately doubled every 10 and 5 years, respectively. They were dramatically high in the very elderly (80-90 years: IHR: 26%, IFR: 9.2%), and also substantial in younger adults (40-50 years: IHR: 0.98%, IFR: 0.042%). Conclusions: These findings support the need for comprehensive preventive measures to help reduce the spread of the virus, even in young or middle-aged adults.

Automated summary

The study in France estimated the SARS-CoV-2 infection hospitalization ratio (IHR) and infection fatality ratio (IFR), which increased with age, especially in men and the elderly. The findings suggest the need for comprehensive preventive measures to reduce virus transmission, even in young or middle-aged adults.