Inferring $R_0$ in emerging epidemics - the effect of common population structure is small

TL;DR

This paper demonstrates that ignoring complex population contact structures when estimating $R_0$ in emerging epidemics generally leads to conservative estimates, enabling robust early control strategies.

Contribution

The study shows that simplifying contact structures to homogeneous assumptions yields conservative estimates of $R_0$, facilitating early epidemic control planning.

Findings

Homogeneous contact assumptions provide conservative $R_0$ estimates.

Neglecting complex structures does not underestimate control efforts.

Simplified models are effective for early outbreak response planning.

Abstract

When controlling an emerging outbreak of an infectious disease it is essential to know the key epidemiological parameters, such as the basic reproduction number $R_0$ and the control effort required to prevent a large outbreak. These parameters are estimated from the observed incidence of new cases and information about the infectious contact structures of the population in which the disease spreads. However, the relevant infectious contact structures for new, emerging infections are often unknown or hard to obtain. Here we show that for many common true underlying heterogeneous contact structures, the simplification to neglect such structures and instead assume that all contacts are made homogeneously in the whole population, results in conservative estimates for $R_0$ and the required control effort. This means that robust control policies can be planned during the early stages of an outbreak, using such conservative estimates of the required control effort.