Computer model tracks SARS.

• Position: Public Health - Research into technology that can predict spread of infectious diseases

A computational method for simulating the spread of flu-like illnesses such as SARS (severe acute respiratory syndrome) that is being developed by a University at Buffalo (N.Y.) geographer may provide policymakers and analysts with new ammunition for studying and predicting the pattern of public-health threats in urban communities. The research uses the tools of geographic information science (GIS) and object-oriented computing to create a realistic projection of how an infectious, flu-like illness would spread throughout a city.

"This type of model allows us to foresee in a more nuanced way what [kind] of risk a community may face," maintains Ling Bian, associate professor of geography in the College of Arts and Sciences. What she is developing differs from some more conventional epidemiological models by taking into account characteristics and behaviors of individuals, the relationships among them and with their environments, and how those interactions change over time and space.

Since the model more explicitly simulates differences in human interaction at different times and locations, it could play a role in helping develop policies to contain more effectively or reduce public health threats. According to Bian, since the spread of an infectious disease throughout a community is a spatial process, GIS uniquely is suited to demonstrate it.

For example, a key contribution of her model is its use of GIS to take into account both the daytime and nighttime locations of individuals. Conventional simulations include just the nighttime, or home, location. This use of multiple points of contact allows for a realistic representation of hew an infection might spread...