糖心TV

Speaker: Ganna Rozhnova (University of Manchester and Lisbon University)

Title: Understanding the role of stochasticity in infectious disease dynamics

Abstract: Childhood infectious diseases have often been taken as a case study and model testing ground because decades of fairly well time resolved data records are available and because of their different dynamics despite the similarities in contagion mechanisms and in infectious, latent, and immunity waning typical times. Cycles are a very striking behaviour of these diseases also seen in a variety of other host-enemy systems, and a case in point is the pattern of recurrent epidemics of many childhood infections. In this talk, I will discuss the role of intrinsic noise (demographic stochasticity), which arises from the discrete nature of a population, in the long-term disease patterns. I will describe a simple driving mechanism of recurrent epidemics which is generic for the majority of the classical models of diseases conferring either lifelong or temporary immunity. I will then address applied questions related to various aspects of the epidemiology of pertussis, measles and rubella. In the first application, I will show how this mechanism can be used to test different assumptions about the immune response of naive hosts to infection with pertussis (immunity waning, immunity waning together with immunity boosting etc.). In the second application, I will discuss how it can help us explain essential differences in the historical patterns exhibited by rubella and measles.