Multilayer networks with higher-order interaction reveal the impact of collective behavior on epidemic dynamics

Epidemic spreading on spatial higher-order network

Higher-order interactions exist widely in mobile populations and are extremely important in spreading epidemics, such as influenza. However, research on high-order interaction modeling of mobile crowds and the propagation dynamics above is still insufficient. Therefore, this study attempts to model and simulate higher-order interactions among mobile populations and explore their impact on epidemic transmission. This study simulated the spread of the epidemic in a spatial high-order network based on agent-based model modeling. It explored its propagation dynamics and the impact of spatial characteristics on it. Meanwhile, we construct state-specific rate equations based on the uniform mixing assumption for further analysis. We found that hysteresis loops are an inherent feature of high-order networks in this space under specific scenarios. The evolution curve roughly presents three different states with the initial value change, showing different levels of the endemic balance of low, medium, and high, respectively. Similarly, network snapshots and parameter diagrams also indicate these three types of equilibrium states. Populations in space naturally form components of different sizes and isolations, and higher initial seeds generate higher-order interactions in this spatial network, leading to higher infection densities. This phenomenon emphasizes the impact of high-order interactions and high-order infection rates in propagation. In addition, crowd density and movement speed act as protective and inhibitory factors for epidemic transmission, respectively, and depending on the degree of movement weaken or enhance the effect of hysteresis loops.

Susceptible-Infected-Susceptible type COVID-19 spread with collective effects

Many models developed to forecast and attempt to understand the COVID-19 pandemic are highly complex, and few take collective behavior into account. As the pandemic progressed individual recurrent infection was observed and simpler susceptible-infected type models were introduced. However, these do not include mechanisms to model collective behavior. Here, we introduce an extension of the SIS model that accounts for collective behavior and show that it has four equilibria. Two of the equilibria are the standard SIS model equilibria, a third is always unstable, and a fourth where collective behavior and infection prevalence interact to produce either node-like or oscillatory dynamics. We then parameterized the model using estimates of the transmission and recovery rates for COVID-19 and present phase diagrams for fixed recovery rate and free transmission rate, and both rates fixed. We observe that regions of oscillatory dynamics exist in both cases and that the collective behavior parameter regulates their extent. Finally, we show that the system exhibits hysteresis when the collective behavior parameter varies over time. This model provides a minimal framework for explaining oscillatory phenomena such as recurring waves of infection and hysteresis effects observed in COVID-19, and other SIS-type epidemics, in terms of collective behavior.

The Impact of Regional COVID-19 Outbreak on Consumers' Risk Perception of Purchasing Food Online

This paper examines the perception of risk associated with the presence of coronavirus in food purchased online and online vs. offline food shopping during the COVID-19 epidemic. The influence of COVID-19 status on risk perception was tested using the data collected from 742 consumers between December 2021 and January 2022. The empirical approach distinguished between the epidemic's status in a province (or region), city, and other areas of the country and applied the ordered logit technique. The regional and citywide epidemic increased the perception that online purchases carry the virus and are riskier than those made offline. Further examination showed that the regional/provincial epidemic created the perception that packaging or social media use were risk factors when purchasing food online. Heterogeneity analysis showed that risk perception was significantly higher in affected cities than in non-affected provinces or other provinces. Risk perception differed across five online food categories, with the highest levels for online-ordered meals and fresh products. Strengthening COVID-19 prevention and control in cities and the province, managing risk due to the handling of food purchased online, and government monitoring of social media use will lessen consumers' risk perceptions and encourage the use of online food offers during epidemics.