Individual behaviours influence the spread of epidemics
A study by Politecnico di Milano, published in Proceedings of the Royal Society A, shows that even a small share of citizens who do not follow preventive measures can put hospital systems under stress, accelerating the spread of epidemics and increasing the peak of infections.
The research, conducted by Fabio Mazza, Marco Brambilla, Carlo Piccardi, and Francesco Pierri from the Department of Electronics, Information and Bioengineering (DEIB), simulated the spreadof an epidemic in Turin, Milan, and Palermo, distinguishing between citizens who comply with health measures and those who do not. The effect is particularly evident when the disease has moderate transmissibility.
The geographic concentration of people who ignore guidelines creates real local hotspots, making it more difficult to contain the epidemic.
The geographic distribution of non-compliant behaviors can significantly alter local infection trajectories, generating marked differences between different city neighborhoods.
Francesco Pierri, Department of Electronics, Information and Bioengineering, coordinator of the study
Fabio Mazza, Marco Brambilla, Carlo Piccardi, Francesco Pierri
A data-driven analysis of the impact of non-compliant individuals on epidemic diffusion in urban settings.
Proc. A 1 October 2025; 481 (2324): 20250511.