Phoebe Asplin (University of Warwick)

Title: Modelling symptom propagation in respiratory pathogens

Abstract:

Symptom propagation occurs when the symptom set an individual experiences is correlated with the symptom set of the individual who infected them. Symptom propagation may dramatically affect epidemiological outcomes, potentially causing clusters of severe disease. Conversely, it could result in chains of mild infection, generating widespread immunity with minimal cost to public health.

I will summarise the accumulating evidence that symptom propagation occurs for many respiratory pathogens, based on our scoping review of the literature (https://doi.org/10.1101/2024.01.05.24300898). Then, I will present a novel compartmental, ordinary differential equation model structure for incorporating different strengths of symptom propagation into models of infectious disease transmission via a single parameter, alpha. Varying alpha tunes the model from having no symptom propagation (alpha=0, as typically assumed) to one where symptoms always propagate (alpha=1). Implementing the model in the case where symptoms are either mild or severe, we’ll then explore the effect of the strength of symptom propagation on epidemiological outcomes, such as the proportion of cases that are severe, and the effectiveness of vaccination strategies. These results are further described in https://doi.org/10.1371/journal.pcbi.1012096.