We quantified the probability of developing symptoms (respiratory or fever >= 37.5 {\deg}C) and critical disease (requiring intensive care or resulting in death) of SARS-CoV-2 positive subjects. 4,326 contacts of SARS-CoV-2 index cases detected in Lombardy, Italy were analyzed, and positive subjects were ascertained via nasal swabs and serological assays. 69.1 \% of all infected individuals aged less than 60 years did not develop symptoms (95\% confidence interval: 66.7-71.4 \%). The risk of symptoms increased with age. 6.9 \% of infected subjects older than 60 years had critical disease, with males at significantly higher risk.
We quantified the probability of developing symptoms (respiratory or fever \geq 37.5 {\deg}C) and critical disease (requiring intensive care or resulting in death) of SARS-CoV-2 positive subjects. 5,484 contacts of SARS-CoV-2 index cases detected in Lombardy, Italy were analyzed, and positive subjects were ascertained via nasal swabs and serological assays. 73.9 \% of all infected individuals aged less than 60 years did not develop symptoms (95\% confidence interval: 71.8-75.9 \%). The risk of symptoms increased with age. 6.6 \% of infected subjects older than 60 years had critical disease, with males at significantly higher risk.
R
>=
\geq
R
4,326
5,484
R
69.1
73.9
R
66.7-71.4
71.8-75.9
R
6.9
6.6