Perspectives on the basic reproductive ratio.

TitlePerspectives on the basic reproductive ratio.
Publication TypeJournal Article
Year of Publication2005
AuthorsHeffernan JM, Smith RJ, Wahl LM
JournalJournal of the Royal Society, Interface / the Royal Society
Date Published2005 Sep 22
KeywordsAnimals, Communicable Diseases, Emerging, Computer Simulation, Disease Outbreaks, Disease Susceptibility, Disease Transmission, Infectious, Epidemiologic Methods, Humans, Incidence, Models, Biological, Population Dynamics, Prevalence, Risk Assessment, Risk Factors

The basic reproductive ratio, R0, is defined as the expected number of secondary infections arising from a single individual during his or her entire infectious period, in a population of susceptibles. This concept is fundamental to the study of epidemiology and within-host pathogen dynamics. Most importantly, R0 often serves as a threshold parameter that predicts whether an infection will spread. Related parameters which share this threshold behaviour, however, may or may not give the true value of R0. In this paper we give a brief overview of common methods of formulating R0 and surrogate threshold parameters from deterministic, non-structured models. We also review common means of estimating R0 from epidemiological data. Finally, we survey the recent use of R0 in assessing emerging diseases, such as severe acute respiratory syndrome and avian influenza, a number of recent livestock diseases, and vector-borne diseases malaria, dengue and West Nile virus.

Alternate JournalJ R Soc Interface