Covid-19 (Corona virus disease 2019) is a viral disease caused by the SARS-CoV-2 corona virus. It was first described in Wuhan at the end of 2019 and was declared a global pandemic by the WHO in March. It spreads mainly through droplet infection from person to person.

The course of the disease varies widely. In addition to asymptomatic infections (asymptomatic course), mostly mild to moderate courses were observed, but also severe pneumonia up to lung failure and death.