Improving estimates of the basic reproductive ratio: using both the mean and the dispersal of transition times.

TitleImproving estimates of the basic reproductive ratio: using both the mean and the dispersal of transition times.
Publication TypeJournal Article
Year of Publication2006
AuthorsHeffernan JM, Wahl LM
JournalTheoretical population biology
Volume70
Issue2
Pagination135-45
Date Published2006 Sep
ISSN0040-5809
KeywordsDisease Outbreaks, Epidemiology, Humans, Models, Statistical, Population Dynamics, Probability
Abstract

In both within-host and epidemiological models of pathogen dynamics, the basic reproductive ratio, R(0), is a powerful tool for gauging the risk associated with an emerging pathogen, or for estimating the magnitude of required control measures. Techniques for estimating R(0), either from incidence data or in-host clinical measures, often rely on estimates of mean transition times, that is, the mean time before recovery, death or quarantine occurs. In many cases, however, either data or intuition may provide additional information about the dispersal of these transition times about the mean, even if the precise form of the underlying probability distribution remains unknown. For example, we may know that recovery typically occurs within a few days of the mean recovery time. In this paper we elucidate common situations in which R(0) is sensitive to the dispersal of transition times about their respective means. We then provide simple correction factors that may be applied to improve estimates of R(0) when not only the mean but also the standard deviation of transition times out of the infectious state can be estimated.

DOI10.1016/j.tpb.2006.03.003
Alternate JournalTheor Popul Biol