The basic reproduction number indicated as R0, also known as the basic reproduction ratio or rate or the basic reproductive rate, is an epidemiologic metric used to describe the contagiousness or transmissibility of infectious agents. R0 is affected by numerous factors such as biological, socio-behavioral, and environmental factors that govern the pathogen transmission among a community and, therefore, is usually estimated with various types of complex mathematical models. R0 for an infectious disease event is reported generally as a single numeric value or from low to high range, and the interpretation is typically presented as if R0 has a value >1, an outbreak is expected to continue and if R0 is <1, then an outbreak is expected to end. In laymen terms, R0 represents the number of individuals that can get infected through an already infected host/individual. Thus R0 gives us a value of secondary cases.