A practical generation-interval-based approach to inferring the strength of epidemics from their speed

Publication date: Available online 10 January 2019Source: EpidemicsAuthor(s): Sang Woo Park, David Champredon, Joshua S. Weitz, Jonathan DushoffAbstractInfectious-disease outbreaks are often characterized by the reproduction number R and exponential rate of growth r. R provides information about outbreak control and predicted final size, but estimating R is difficult, while r can often be estimated directly from incidence data. These quantities are linked by the generation interval – the time between when an individual is infected by an infector, and when that infector was infected. It is often infeasible to obtain the exact shape of a generation-interval distribution, and to understand how this shape affects estimates of R. We show that estimating generation interval mean and variance provides insight into the relationship between R and r. We use examples based on Ebola, rabies and measles to explore approximations based on gamma-distributed generation intervals, and find that use of these simple approximations are often sufficient to capture the r−−R relationship and provide robust estimates of R.

Source: Epidemics - January 11, 2019 Category: Epidemiology Source Type: research