Replacing Ill Workers with Healthy Ones Accelerates Some Epidemics

By Joy Daughtery Dickinson, Executive Editor

As disease outbreaks make their way through your facility, the sick people stay home, and healthy staff come in. However, that might not be the best way to stop spread of the infection, according to research published Aug. 1 in Nature Physics.

A group that included a mathematical biologist and a theoretical physicist set out to quantify the risk to the population in such a scenario. The group found that when you replace sick people with healthy ones, you accelerate the infection’s spread. They examined 17 years of data on influenza and dengue. They found that exchanging sick people for well ones appears to accelerate the spread of influenza, but not dengue, which is spread by mosquitoes.

“We didn’t see a strong signal in diseases where we didn’t expect it,” says Laurent Hébert-Dufresne, a theoretical physicist and James S. McDonnell Fellow at the Santa Fe Institute in New Mexico.

Samuel Scarpino, a mathematical biologist and assistant professor at the Burlington-based University of Vermont, hopes this effect will be integrated into epidemiological models. “Models where you start to incorporate slightly more realistic human behavior are essential if we’re going to make high-fidelity public health and clinical decisions,” he says. (To keep up with news on infectious diseases, read our Hospital Infection Control & Prevention publication. To keep up with employee health issues, read Hospital Employee Health.)