Coupling Fear and Contagion for Modeling Epidemic Dynamics

Kirti Jain, Vasudha Bhatnagar, Sadanand Prasad, Sharanjit Kaur

Abstract: The emotion of fear related to an infectious disease not only influences an individual's behavior but also transmits to social contacts. Therefore, modeling human behavior is a precursor to reliable estimates of epidemic size and duration. In this paper, we present an abstract model of fear, which is realized using an Individual-based Fear Model (IBFM). In this model, fear is coupled with contagion to study the influence of human behavior on epidemic dynamics. Since fear is an inherent characteristic of an individual that determines susceptibility to infection, the model discerns between individuals by maintaining a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">fear-index</i> . Variations in innate fear levels in populations with cultural differences are also accommodated. Since the fear level of individuals is affected by the changing size of the epidemic, IBFM provides a mechanism to update fear in the population realistically. The mechanism gives rise to multiple epidemic waves observed in real-world epidemics. We compare the epidemic dynamics for IBFM and differential equation-based realization of the abstract model. We present a detailed empirical study to understand the interplay of fear and contagion in IBFM.