Proceedings of the 2009 Winter Simulation Conference M. D. Rossetti, R. R. Hill, B. Johansson, A. Dunkin and R. G. Ingalls, eds. A PANDEMIC INFLUENZA SIMULATION MODEL FOR PREPAREDNESS PLANNING Ozgur M. Araz Tim W. Lant Megan Jehn John W. Fowler Industrial, Systems and Operations Engineering Department Decision Theater School of Health Management and Policy Arizona State University PO Box 878409 W. P. Carey School of Business PO Box 874506 PO Box 875906 Arizona State University Arizona State University Tempe, AZ, 85287-5906 , USA Tempe, AZ, 85287-8409, USA Tempe, AZ 85287-4506, USA ABSTRACT Pandemic influenza continues to be a national and international public health concern that has received significant attention recently with the recent swine flu outbreak worldwide. Many countries have developed and updated their preparedness plans for pandemic influenza. School closure has been recommended as one of the best ways to protect children and indeed all susceptible individuals in a community during a possible disease outbreak. In this paper, we present a geospatial and temporal disease spread model for pandemic influenza affecting multiple communities. School closure, one of the social distancing policies, is investigated in this paper with several questions such as: at what level should schools be closed, for how long should they be kept closed, and how should be the re-opening decisions made. These questions are considered in terms of minimizing: the total infection cases, total mortalities, and the impact on educational services to school children. 1 INTRODUCTION The World Health Organization (WHO) has reported that the avian influenza (H5N1) virus is threatening human life worldwide, as it may soon have the ability to efficiently transmit from person to person which would likely cause a pandemic (WHO 2005). Preparedness plans for pandemic influenza generally focus on establishing efficient mitigation strategies for inter-related communities and providing adequate medical services. Several decisions need to be made before, during, and after the pandemic outbreak to manage the impacts of the disease successfully, minimize loss of life, and minimize the effect on daily business operations. However, because the population that will be potentially affected by pandemic influenza is very large and diverse, different strategies, including non-pharmaceutical and pharmaceutical interventions, will inevitably need to be employed in different communities. In this paper, we develop an age structured geospatial disease spread model to estimate the spread pattern of the disease geographically in Arizona, U.S. over time. The simulation model divides the state into multiple communities, which are the counties of the state. Our objective in this paper is to study one of the non-pharmaceutical mitigation policies, school closure, during an outbreak of pandemic influenza. The presented simulation model of this paper allows decision makers to test various school closure strategies in terms of limiting activities in schools in each county separately at different times or in all schools in the state at once, closing schools at each county separately at different times or closing all schools at once by a state-wide declaration. We also quantify the effects of the reopening decision for school closures without using any pharmaceutical interventions. In the rest of the paper, we first present a literature review and then state the major contribution of this paper to pandemic flu modeling. Next we give the mathematical details of the simulation model with its structure. After presenting the analysis for different scenarios we present our conclusions in the last section. © IEEE 2009. This article is free to access and download, along with rights for full text and data mining, re-use and analysis.