Simulating the effects of mobility restrictions in the spread of SARS-CoV-2 in metropolitan areas in Portugal

PLoS One. 2022 Sep 9;17(9):e0274286. doi: 10.1371/journal.pone.0274286. eCollection 2022.

Abstract

Commuting flows and long-distance travel are important spreading factors of viruses and particularly airborne ones. Therefore, it is relevant to examine the association among diverse mobility scenarios and the spatial dissemination of SARS-CoV-2 cases. We intended to analyze the patterns of virus spreading linked to different mobility scenarios, in order to better comprehend the effect of the lockdown measures, and how such measures can be better informed. We simulated the effects of mobility restrictions in the spread of SARS-CoV-2 amongst the municipalities of two metropolitan areas, Lisbon (LMA) and Porto (PMA). Based on an adapted SEIR (Suscetible-Exposed-Infected-Removed) model, we estimated the number of new daily infections during one year, according to different mobility scenarios: restricted to essential activities, industrial activities, public transport use, and a scenario with unrestricted mobility including all transport modes. The trends of new daily infections were further explored using time-series clustering analysis, using dynamic time warping. Mobility restrictions resulted in lower numbers of new daily infections when compared to the unrestricted mobility scenario, in both metropolitan areas. Between March and September 2020, the official number of new infections followed overall a similar timeline to the one simulated considering only essential activities. At the municipal level, trends differ amongst the two metropolitan areas. The analysis of the effects of mobility in virus spread within different municipalities and regions could help tailoring future strategies and increase the public acceptance of eventual restrictions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • COVID-19* / epidemiology
  • COVID-19* / prevention & control
  • Communicable Disease Control / methods
  • Humans
  • Portugal / epidemiology
  • SARS-CoV-2*
  • Travel

Grants and funding

This work was financed by national funds through FCT—Portuguese Foundation for Science and Technology, I.P., under the framework of the project “TRIAD - health Risk and social vulnerability to Arboviral Diseases in mainland Portugal” [PTDC/GES -OUT/30210/2017] and by the Research Unit UIDB/00295/2020 and UIDP/00295/2020. This study was also funded by FEDER through the Operational Programme Competitiveness and Internationalization and national funding from the Foundation for Science and Technology – FCT (Portuguese Ministry of Science, Technology and Higher Education) under the EPIUnit (UIDB/04750/2020). AIR was supported by National Funds through FCT, under the programme of ‘Stimulus of Scientific Employment – Individual Support’ within the contract CEECIND/02386/2018. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.