Human mobility and population heterogeneity in the spread of an epidemic

Little is known on how different levels of population heterogeneity and different patterns of human mobility would affect the course of an epidemic in terms of timing and impact. By employing a large-scale spatially-explicit individual-based model, based on a highly detailed model of the European populations and on a carefully analysis of air and railway transportation data, we provide quantitative measures of their effects at European level. Our results show that Europe must prepare to face a fast diffusion of an epidemic, mostly because of the early importation of the first cases from abroad and the synchronization of the local epidemics, determined by the high mobility of the European population. We found that the cumulative attack rate is positively correlated with the average households size and the fraction of students in the population, and negatively correlated with the fraction of inactive population. These results have potentially strong implications in terms of mitigation and control, and suggest that the effectiveness of interventions as antiviral treatment and prophylaxis, schools closure and travel restrictions should be evaluated on a country basis.