Disease outbreaksFactors influencing the timing of infectious disease outbreaks
The delay between the time when a disease outbreak becomes possible and when it actually happens depends chiefly on how frequently infection is introduced to the population and how quickly the number of cases caused by a single individual increases, according to new research. The research lays the theoretical groundwork for a disease forecasting system that could give public health officials time to prepare for-or possibly even prevent-certain outbreaks in the future.
The delay between the time when a disease outbreak becomes possible and when it actually happens depends chiefly on how frequently infection is introduced to the population and how quickly the number of cases caused by a single individual increases, according to new research from the University of Georgia.
The findings, just published in the Royal Society journal Interface, lay the theoretical groundwork for a disease forecasting system that could give public health officials time to prepare for-or possibly even prevent-certain outbreaks in the future.
Infectious diseases pose a serious threat to public health around the world, as recent outbreaks of emerging diseases such as Zika and re-emerging ones such as measles attest. An early warning system for infectious diseases could not only save lives but also allow public health resources to be used more efficiently and effectively. UGA says that developing such a system is the goal of Project AERO, a research collaborative led by John M. Drake, a professor in the UGA Odum School of Ecology, director of the Center for the Ecology of Infectious Diseases, and the study’s senior author. The paper is one of the project’s first outcomes.
Project AERO applies the theory of “critical slowing down” to infectious diseases. Critical slowing down is the idea that as complex systems approach a tipping point-a threshold beyond which the system is vulnerable to collapse-they exhibit recognizable patterns that can alert observers that the tipping point is imminent.
In the case of an infectious disease system, the patterns appear in public health case reports and the tipping point is the point at which each infected individual tends to pass the infection on to more than one other person. Once that happens, the population is at risk of an outbreak.
But in most cases major outbreaks don’t occur as soon as they are theoretically possible, according to Christopher J. Dibble, a postdoctoral associate at the Odum School who led the study.
“We know that there’s some amount of delay between the theoretical point and the first major outbreak, and this effort was aimed in part at finding some likely values for that waiting time and in part to discern what drives it,” Dibble said.
