Epidemiology - Spreading Ι

Political and environmental factors – e.g., regional conflicts and global warming – increase large-scale migrations, posing extraordinary societal challenges to policy makers of destination countries. A common concern is that such a massive arrival of people – often from a country with a disrupted healthcare system – can increase the risk of vaccinepreventable diseases outbreaks like measles. We analyze human flows of 3.5M Syrian refugees in Turkey inferred from massive mobile phone data to verify this concern.

The spreading phenomenon has characterized for a long time, problems arising from the dis- eases contagion to the diffusion of information [1]. The behaviour of the interacting agents has been usually modelled in two main ways accordingly to the size of the spatial support where the spreading occurs. On one side, we have contact network models where the interact- ing agents are confined in a restricted physical or virtual space where the transmission be- tween individuals in contact with each other.

Our understanding of the dynamics of complex networked systems has increased significantly in the last two decades. However, most of our knowledge is built upon assuming pairwise relations among the system's components. This is often an oversimplification, for instance, in social interactions that occur frequently within groups. To overcome this limitation, here we study the dynamics of social contagion on hypergraphs. We develop an analytical framework and provide numerical results for arbitrary hypergraphs, which we also support with Monte Carlo simulations.

Human movement is key to the spread of infectious diseases, including COVID-19. Hence, it is also key to the control and containment of the disease itself [1]. The flow of people from places to places is not uniform across all links in a city. Some links—edges of the human flow network connecting two nodes corresponding to two locales—exhibit particularly high flows, while others are experience less intense flows despite the fact that they may connect two busy places. This leads to some heterogeneity in both the spreadability and vulnerability of the disease.