The epidemiology of COVID-19 infection will be understood by the
relationship between the intensity of action on public well-being and the rate of its
transmission control. The virus is a chemical substance that is vulnerable until it
invades the living body. The molecular assembly of the virus contains RNA genome
and proteins. When 2019-nCoV enters the host cell of the living body, it continues its
progeny by the replication process. It starts to make molecular assemblies for every
new virion produced through replication and transcription. Though the incubation time
is accounted for to range between 1 to 14 days, the median incubation period is 5 days.
According to a recent survey on COVID-19 patients, 80 percent of patients are
asymptomatic. This book chapter describes the life cycle and spread of 2019-nCoV,
CFR, clinical manifestations, diagnosis, and prevention of COVID-19.
Keywords: 2019-nCoV, COVID-19, HRCT, Life cycle, Prevention, Symptoms, Transmission.
