Lockdowns result in changes in human mobility which may impact the epidemiologic dynamics of SARS-CoV-2

Nishant Kishore,Caroline O Buckee,Ayesha S Mahmud,Pamela P Martinez,Rebecca Kahn,Pablo M De Salazar

doi:10.1038/s41598-021-86297-w

Abstract

In response to the SARS-CoV-2 pandemic, unprecedented travel restrictions and stay-at-home orders were enacted around the world. Ultimately, the public’s response to announcements of lockdowns—defined as restrictions on both local movement or long distance travel—will determine how effective these kinds of interventions are. Here, we evaluate the effects of lockdowns on human mobility and simulate how these changes may affect epidemic spread by analyzing aggregated mobility data from mobile phones. We show that in 2020 following lockdown announcements but prior to their implementation, both local and long distance movement increased in multiple locations, and urban-to-rural migration was observed around the world. To examine how these behavioral responses to lockdown policies may contribute to epidemic spread, we developed a simple agent-based spatial model. Our model shows that this increased movement has the potential to increase seeding of the epidemic in less urban areas, which could undermine the goal of the lockdown in preventing disease spread. Lockdowns play a key role in reducing contacts and controlling outbreaks, but appropriate messaging surrounding their announcement and careful evaluation of changes in mobility are needed to mitigate the possible unintended consequences.

Highlights

In response to the SARS-CoV-2 pandemic, unprecedented travel restrictions and stay-at-home orders were enacted around the world
We find that city centers around the US showed a spike in day-time mobility prior to March 16, 2020, suggestive of mobility related to preparations for these restrictions (Fig. 1).This pattern was observed in urban centers across the U.S, with all locations showing a large increase in "Morning" population following the announcement of COVID-19 travel and social gathering restrictions, followed by a dramatic decline upon its implementation
The extent to which they were effective in containing the spread of SARS-CoV-2 remains unclear, but the impact of physical distancing policies on human mobility is measurable at scale for the first time due to the widespread availability of data from mobile phones

Summary

Introduction

We show that in 2020 following lockdown announcements but prior to their implementation, both local and long distance movement increased in multiple locations, and urbanto-rural migration was observed around the world To examine how these behavioral responses to lockdown policies may contribute to epidemic spread, we developed a simple agent-based spatial model. In response to the SARS-CoV-2 pandemic, unprecedented travel restrictions and stay-at-home orders were enacted around the world almost simultaneously These ranged from restrictions on human movement on a local scale to travel restrictions on regional and international scales. We evaluate the effect of lockdown related travel behavior on epidemic spread by analyzing aggregated mobility data from mobile phones from multiple countries including India, France, Spain, Bangladesh, and the USA, on local and national spatial scales. This work highlights the importance of messaging and close evaluation of changes in local travel networks in the implementation of outbreak related travel restrictions

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Conclusion