Research applies math model to better predict spread of epidemic diseases

The lurking threat of a major epidemic over the last decade has captured the attention of the international media and the public, with fears running rampant about the avian flu spreading to humans or H1N1 flu mutating at such a rate that it couldn't be controlled.

Researchers at the University of Colorado Denver have received an American Recovery and Reinvestment Act (ARRA) grant to harness an opportunity created by recent mathematical advances that can systematically track the spread of wildfires, weather systems and climate patterns. The UC Denver researchers plan to adapt these new tracking techniques to the movements of epidemic diseases.

"When looking at the current climate changes combined with the exponential growth of the human population, long distance travel made easier than ever, and a multitude of other factors, humanity is at the brink of the emergence of new and possibly devastating infectious epidemic diseases, as well as the possible re-emergence of resistant strains of older diseases," said Loren Cobb, Ph.D., research associate professor in the department of mathematical and statistical sciences at UC Denver and principal investigator on the study. "A reliable mathematical system could dramatically improve our ability to track epidemics and to predict their short-term spatial movements—which would have a huge potential impact on public health."

Monitoring and suppressing small outbreaks so that they do not become a global emergency has become the daily routine of public health systems in many parts of the world. Cobb and colleagues say the objective of the UC Denver project is to develop a spatial epidemic simulation system, capable of incorporating and adapting real-time data such as incidence, prevalence, and mortality reports from locations around the world, while the model is running. The technology and advanced theory for this spatial data assimilation have only recently been developed in the fields of climate science, meteorology, and wildfire studies, where it has had a major impact.

"This is exciting new technology and we anticipate it can create a dramatic improvement in the ability to forecast epidemics, having a beneficial impact on public health by enabling more effective policies and the concentration of resources to save lives," Cobb said. "Given the global nature of pandemic disease and the dangers in failing to control a lethal outbreak, it would not be an exaggeration to suggest that the size of the community impacted by the benefits of this type of technology could be the world's entire population."

This study project will incorporate mass population movements that may occur as a result of a hypothetical epidemic, using a mathematical model that can update itself in real time, significantly improving predictions of the geographical spread of the disease. The new capability could make it possible for public health authorities to concentrate their efforts where they matter most, and for the government to adopt effective policies anticipating the response of the population.

The computerized tracking system will be validated against historical as well as artificial test data streams. The project will culminate with an operational exercise to be performed with the Office of Emergency Preparedness in the state of Colorado's department of public health and environment, along with the Colorado School of Public Health at UC Denver. This exercise will test the ability of the modeling system to provide decision makers with timely and useful spatial information on a dynamic digital map.

"This effort will ultimately be judged successful if public health departments come to rely upon spatial simulations to give them information on the likely progress of fast-moving epidemic outbreaks," Cobb said.

The two-year, $710,000 study will be supervised by the National Library of Medicine. Cobb and colleagues expect to demonstrate the results of their research early this year.