Estimates of ascertainment rate, risk of being severe or critical for detected cases, risk of death for critical or severe cases, and infection fatality ratio (95% confidence interval in brackets).

In Grasselli et al. [21], which we use to estimate death risks, individuals up to 39 years old are grouped into two groups corresponding to 0–19 and 20–39. No deaths were registered in the youngest group: rates for the 20–29 and 30–39 were obtained from the second group. The Infection Fatality Rate is obtained by appropriately combining the other five columns.