SARS-CoV-2 is the name of the "coronavirus 2 of severe acute respiratory syndrome" that causes covid-19 disease. It first appeared in Wuhan City, China, in December 2019. The genome of the virus is classified as positive single-stranded RNA, as it forms a single RNA chain. It stays active outside the body for several days on surfaces such as marble or stainless steel, from where it is lifted by contact and thus reaches eyes, mouth or nose for a new contagion; it also enters the body through infected saliva microdropths that are breathed. See sars .
