UTA Department of Mathematics

Applied Mathematics Seminar

Date/Time/Room: Thursday (2/16/2006) at 2:00pm in 304 Pickard Hall

Speaker: Dr. Junling Ma, Postdoctoral Fellow
Department of Mathematics & Statistics, McMaster University


"Why does influenza come back every winter?"

Abstract: A key characteristic of Influenza epidemics is that they occur in the winter. Traditionally, this seasonality is thought to arise from seasonal changes in transmission rates. However, fitting a seasonally forced transmission model to influenza mortality time series reveals that the periodic introduction of new flu variants may also play a fundamental role. In fact, we can fit the mortality curve very well with no seasonal variation in transmission rates.

In this talk, we will see that flu-like cyclic dynamics can emerge from the coupling of the epidemic process (described by a deterministic compartmental model) and the viral mutation process (described by a nonhomogeneous Poisson process). While not required to generate periodicity, seasonal forcing ensures that the average period between epidemics is exactly one year.The results that I will describe suggest a variety of ways to develop tractable mathematical models that can further increase our understanding of influenza dynamics and evolution.