MOOD project is at the forefront of European research of infectious disease surveillance and modelling from a data science perspective, investigating the impact of global warming on disease outbreaks, and proposing innovations for building of One Health systems across Europe and the world.
In the table below are listed all MOOD publications. Use the filter to select the most relevant articles.
9.
Pullano, Giulia; Domenico, Laura Di; Colizza, Vittoria
Telework and other measures reducing the presence at work to slow down COVID-19pdm in France (Sept 2020) Technical Report
2021.
Abstract | Links | BibTeX | Tags: COVID-19, epidemiology, France, measures
@techreport{nokey,
title = {Telework and other measures reducing the presence at work to slow down COVID-19pdm in France (Sept 2020)},
author = {Giulia Pullano and Laura Di Domenico and Vittoria Colizza},
url = {http://www.epicx-lab.com/uploads/9/6/9/4/9694133/inserm_covid-19-telework.pdf},
year = {2021},
date = {2021-11-28},
abstract = {COVID-19 pandemic shows a clear and substantial increase of activity in France since summer 2020.
Certain regions are in highly vulnerable situations, with large number of hospitalizations per day,
important fraction of ICU beds occupied, and short doubling times (<2 weeks). At the same time,
activities are increasing since the beginning of September, with the reopening of schools and the return
to work after summer holidays (not yet reaching pre-pandemic levels), leaving further opportunities for
the virus to spread. Using mathematical models calibrated to the observed epidemic trajectory in each
region, this report analyzes possible scenarios of telework and other means to reduce the presence at
work, and assesses their impact on the epidemic trajectory in the following weeks. Numerical results
confirm that telework and other measures reducing the presence at work under realistic assumptions
may decelerate the epidemic curve gaining few weeks of time, but would not be enough to revert the
increasing tendency of the curve, unless coupled with other contact reduction measures. The situation is
particularly critical in IDF. In these conditions, if nothing changes, the level of hospitalizations of the peak
of the first wave is expected to be reached in IDF in about a month from now (earlier, if return to work
increases in the following weeks as suggested by the trend in the data and if not contrasted by telework).
Explicit guidance on telework and interventions to facilitate its application to all professional categories
who can adopt it should be urgently provided. This standard should be kept as a routine measure of
epidemic control for several months. More restrictive measures involving the closure of certain activities
to reduce avoidable contacts are urgently needed to slow down the epidemic increase to levels that are
manageable by the healthcare system. This analysis cannot account for the effect of the measures
implemented today},
keywords = {COVID-19, epidemiology, France, measures},
pubstate = {published},
tppubtype = {techreport}
}
COVID-19 pandemic shows a clear and substantial increase of activity in France since summer 2020.
Certain regions are in highly vulnerable situations, with large number of hospitalizations per day,
important fraction of ICU beds occupied, and short doubling times (<2 weeks). At the same time,
activities are increasing since the beginning of September, with the reopening of schools and the return
to work after summer holidays (not yet reaching pre-pandemic levels), leaving further opportunities for
the virus to spread. Using mathematical models calibrated to the observed epidemic trajectory in each
region, this report analyzes possible scenarios of telework and other means to reduce the presence at
work, and assesses their impact on the epidemic trajectory in the following weeks. Numerical results
confirm that telework and other measures reducing the presence at work under realistic assumptions
may decelerate the epidemic curve gaining few weeks of time, but would not be enough to revert the
increasing tendency of the curve, unless coupled with other contact reduction measures. The situation is
particularly critical in IDF. In these conditions, if nothing changes, the level of hospitalizations of the peak
of the first wave is expected to be reached in IDF in about a month from now (earlier, if return to work
increases in the following weeks as suggested by the trend in the data and if not contrasted by telework).
Explicit guidance on telework and interventions to facilitate its application to all professional categories
who can adopt it should be urgently provided. This standard should be kept as a routine measure of
epidemic control for several months. More restrictive measures involving the closure of certain activities
to reduce avoidable contacts are urgently needed to slow down the epidemic increase to levels that are
manageable by the healthcare system. This analysis cannot account for the effect of the measures
implemented today
Certain regions are in highly vulnerable situations, with large number of hospitalizations per day,
important fraction of ICU beds occupied, and short doubling times (<2 weeks). At the same time,
activities are increasing since the beginning of September, with the reopening of schools and the return
to work after summer holidays (not yet reaching pre-pandemic levels), leaving further opportunities for
the virus to spread. Using mathematical models calibrated to the observed epidemic trajectory in each
region, this report analyzes possible scenarios of telework and other means to reduce the presence at
work, and assesses their impact on the epidemic trajectory in the following weeks. Numerical results
confirm that telework and other measures reducing the presence at work under realistic assumptions
may decelerate the epidemic curve gaining few weeks of time, but would not be enough to revert the
increasing tendency of the curve, unless coupled with other contact reduction measures. The situation is
particularly critical in IDF. In these conditions, if nothing changes, the level of hospitalizations of the peak
of the first wave is expected to be reached in IDF in about a month from now (earlier, if return to work
increases in the following weeks as suggested by the trend in the data and if not contrasted by telework).
Explicit guidance on telework and interventions to facilitate its application to all professional categories
who can adopt it should be urgently provided. This standard should be kept as a routine measure of
epidemic control for several months. More restrictive measures involving the closure of certain activities
to reduce avoidable contacts are urgently needed to slow down the epidemic increase to levels that are
manageable by the healthcare system. This analysis cannot account for the effect of the measures
implemented today
8.
Pullano, Giulia; Domenico, Laura Di; Sabbatini, Chiara E.; Colizza, Vittoria
Expected impact of exit strategies after the second lockdown - France, Nov 2020 Technical Report
2021.
Abstract | Links | BibTeX | Tags: COVID-19, France, lock-down, measures
@techreport{nokey,
title = {Expected impact of exit strategies after the second lockdown - France, Nov 2020},
author = {Giulia Pullano and Laura Di Domenico and Chiara E. Sabbatini and Vittoria Colizza},
url = {https://www.epicx-lab.com/uploads/9/6/9/4/9694133/inserm_covid-19-lockdown_schools_open-20201117.pdf},
year = {2021},
date = {2021-11-17},
abstract = {This report is an update of previous reports (Report #19, Report #21) on the expected impact of the
second lockdown implemented in France on Friday, October 30 to suppress the second wave of COVID-19
epidemic. We provide updated projections simulating a mild lockdown with schools open informed on the
estimates on mobility reduction recorded during the first week of lockdown from mobile phone data
(Report #22), and explore different exit strategies. The current report focuses on Île-de-France; analyses
for other regions will follow. },
keywords = {COVID-19, France, lock-down, measures},
pubstate = {published},
tppubtype = {techreport}
}
This report is an update of previous reports (Report #19, Report #21) on the expected impact of the
second lockdown implemented in France on Friday, October 30 to suppress the second wave of COVID-19
epidemic. We provide updated projections simulating a mild lockdown with schools open informed on the
estimates on mobility reduction recorded during the first week of lockdown from mobile phone data
(Report #22), and explore different exit strategies. The current report focuses on Île-de-France; analyses
for other regions will follow.
second lockdown implemented in France on Friday, October 30 to suppress the second wave of COVID-19
epidemic. We provide updated projections simulating a mild lockdown with schools open informed on the
estimates on mobility reduction recorded during the first week of lockdown from mobile phone data
(Report #22), and explore different exit strategies. The current report focuses on Île-de-France; analyses
for other regions will follow.
7.
Manica, Mattia; Guzzetta, Giorgio; Riccardo, Flavia; Valenti, Antonio; Poletti, Piero; Marziano, Valentina; Trentini, Filippo; Andrianou, Xanthi; Urdiales, Alberto Mateo; Manso, Martina; Fabiani, Massimo; Vescio, Maria Fenicia; Spuri, Matteo; Petrone, Daniele; Bella, Antonino; Iavicoli, Sergio; Ajelli, Marco; Brusaferro, Silvio; Pezzotti, Patrizio; Merler, Stefano
Impact of tiered restrictions on human activities and the epidemiology of the second wave of COVID-19 in Italy Journal Article
In: Nature Communications, vol. 12, no. 4570, 2021.
Abstract | Links | BibTeX | Tags: COVID-19, Italy, measures, Public Health, surveillance
@article{Manica2021.01.10.21249532,
title = {Impact of tiered restrictions on human activities and the epidemiology of the second wave of COVID-19 in Italy},
author = {Mattia Manica and Giorgio Guzzetta and Flavia Riccardo and Antonio Valenti and Piero Poletti and Valentina Marziano and Filippo Trentini and Xanthi Andrianou and Alberto Mateo Urdiales and Martina Manso and Massimo Fabiani and Maria Fenicia Vescio and Matteo Spuri and Daniele Petrone and Antonino Bella and Sergio Iavicoli and Marco Ajelli and Silvio Brusaferro and Patrizio Pezzotti and Stefano Merler},
url = {https://www.medrxiv.org/content/early/2021/02/24/2021.01.10.21249532},
doi = {10.1101/2021.01.10.21249532 },
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Nature Communications},
volume = {12},
number = {4570},
publisher = {Cold Spring Harbor Laboratory Press},
abstract = {To counter the second COVID-19 wave in autumn 2020, the Italian government introduced a system of physical distancing measures organized in progressively restrictive tiers (coded as yellow, orange, and red) and imposed on a regional basis according to epidemiological risk assessments. The individualstextquoteright attendance to locations outside the residential settings was progressively reduced with tiers, but less than during the national lockdown against the first COVID-19 wave in the spring. The reproduction number Rt decreased below the epidemic threshold in 85 out of 107 provinces after the introduction of the tier system, reaching average values of about 0.99, 0.89 and 0.77 in the yellow, orange and red tier, respectively. We estimate that the reduced transmissibility resulted in averting about 37% of the hospitalizations between November 5 and November 25, 2020. These results are instrumental to inform public health efforts aimed at preventing future resurgence of cases. Competing Interest Statement: M.A. has received research funding from Seqirus. The funding is not related to COVID-19. All other authors declare no competing interest. Funding StatementM.M., G.G., V.M., P. Poletti, F.T., and S.M. acknowledge funding from EU Grant 874850 MOOD (cataloged as MOOD 000). The contents of this publication are the sole responsibility of the authors and do not necessarily reflect the views of the funderAuthor DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below: No IRB was required for this analysis. All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesData are available from the corresponding author upon reasonable request.},
keywords = {COVID-19, Italy, measures, Public Health, surveillance},
pubstate = {published},
tppubtype = {article}
}
To counter the second COVID-19 wave in autumn 2020, the Italian government introduced a system of physical distancing measures organized in progressively restrictive tiers (coded as yellow, orange, and red) and imposed on a regional basis according to epidemiological risk assessments. The individualstextquoteright attendance to locations outside the residential settings was progressively reduced with tiers, but less than during the national lockdown against the first COVID-19 wave in the spring. The reproduction number Rt decreased below the epidemic threshold in 85 out of 107 provinces after the introduction of the tier system, reaching average values of about 0.99, 0.89 and 0.77 in the yellow, orange and red tier, respectively. We estimate that the reduced transmissibility resulted in averting about 37% of the hospitalizations between November 5 and November 25, 2020. These results are instrumental to inform public health efforts aimed at preventing future resurgence of cases. Competing Interest Statement: M.A. has received research funding from Seqirus. The funding is not related to COVID-19. All other authors declare no competing interest. Funding StatementM.M., G.G., V.M., P. Poletti, F.T., and S.M. acknowledge funding from EU Grant 874850 MOOD (cataloged as MOOD 000). The contents of this publication are the sole responsibility of the authors and do not necessarily reflect the views of the funderAuthor DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below: No IRB was required for this analysis. All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesData are available from the corresponding author upon reasonable request.
6.
Lemey, Philippe; Ruktanonchai, Nick; Hong, Samuel L; Colizza, Vittoria; Poletto, Chiara; den Broeck, Frederik Van; Gill, Mandev S; Ji, Xiang; Levasseur, Anthony; Munnink, Bas B Oude; others,
Untangling introductions and persistence in COVID-19 resurgence in Europe Journal Article
In: Nature, vol. 595, no. 7869, pp. 713–717, 2021.
Abstract | Links | BibTeX | Tags: big data, COVID-19, epidemiology, Europe, measures, mobility
@article{lemey2021untangling,
title = {Untangling introductions and persistence in COVID-19 resurgence in Europe},
author = {Philippe Lemey and Nick Ruktanonchai and Samuel L Hong and Vittoria Colizza and Chiara Poletto and Frederik Van den Broeck and Mandev S Gill and Xiang Ji and Anthony Levasseur and Bas B Oude Munnink and others},
doi = {https://doi.org/10.1038/s41586-021-03754-2},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Nature},
volume = {595},
number = {7869},
pages = {713--717},
publisher = {Nature Publishing Group},
abstract = {After the first wave of SARS-CoV-2 infections in spring 2020, Europe experienced a resurgence of the virus starting in late summer 2020 that was deadlier and more difficult to contain1. Relaxed intervention measures and summer travel have been implicated as drivers of the second wave2. Here we build a phylogeographical model to evaluate how newly introduced lineages, as opposed to the rekindling of persistent lineages, contributed to the resurgence of COVID-19 in Europe. We inform this model using genomic, mobility and epidemiological data from 10 European countries and estimate that in many countries more than half of the lineages circulating in late summer resulted from new introductions since 15 June 2020. The success in onward transmission of newly introduced lineages was negatively associated with the local incidence of COVID-19 during this period. The pervasive spread of variants in summer 2020 highlights the threat of viral dissemination when restrictions are lifted, and this needs to be carefully considered in strategies to control the current spread of variants that are more transmissible and/or evade immunity. Our findings indicate that more effective and coordinated measures are required to contain the spread through cross-border travel even as vaccination is reducing disease burden.},
keywords = {big data, COVID-19, epidemiology, Europe, measures, mobility},
pubstate = {published},
tppubtype = {article}
}
After the first wave of SARS-CoV-2 infections in spring 2020, Europe experienced a resurgence of the virus starting in late summer 2020 that was deadlier and more difficult to contain1. Relaxed intervention measures and summer travel have been implicated as drivers of the second wave2. Here we build a phylogeographical model to evaluate how newly introduced lineages, as opposed to the rekindling of persistent lineages, contributed to the resurgence of COVID-19 in Europe. We inform this model using genomic, mobility and epidemiological data from 10 European countries and estimate that in many countries more than half of the lineages circulating in late summer resulted from new introductions since 15 June 2020. The success in onward transmission of newly introduced lineages was negatively associated with the local incidence of COVID-19 during this period. The pervasive spread of variants in summer 2020 highlights the threat of viral dissemination when restrictions are lifted, and this needs to be carefully considered in strategies to control the current spread of variants that are more transmissible and/or evade immunity. Our findings indicate that more effective and coordinated measures are required to contain the spread through cross-border travel even as vaccination is reducing disease burden.
5.
Guzzetta, Giorgio; Riccardo, Flavia; Marziano, Valentina; Poletti, Piero; Trentini, Filippo; Bella, Antonino; Andrianou, Xanthi; Manso, Martina Del; Fabiani, Massimo; Bellino, Stefania; Boros, Stefano; Urdiales, Alberto Mateo; Vescio, Maria Fenicia; Piccioli, Andrea; Brusaferro, Silvio; Rezza, Giovanni; Pezzotti, Patrizio; Ajelli, Marco; Merler, Stefano; Group, COVID-19 Working
Impact of a Nationwide Lockdown on SARS-CoV-2 Transmissibility, Italy Bachelor Thesis
2021.
Abstract | Links | BibTeX | Tags: COVID-19, Italy, lock-down, measures
@bachelorthesis{nokey,
title = {Impact of a Nationwide Lockdown on SARS-CoV-2 Transmissibility, Italy},
author = {Giorgio Guzzetta and Flavia Riccardo and Valentina Marziano and Piero Poletti and Filippo Trentini and Antonino Bella and Xanthi Andrianou and Martina Del Manso and Massimo Fabiani and Stefania Bellino and Stefano Boros and Alberto Mateo Urdiales and Maria Fenicia Vescio and Andrea Piccioli and Silvio Brusaferro and Giovanni Rezza and Patrizio Pezzotti and Marco Ajelli and Stefano Merler and COVID-19 Working Group},
doi = {10.3201/eid2701.202114},
year = {2021},
date = {2021-01-01},
journal = {Emerging Infectious Diseases},
volume = {27},
number = {1},
abstract = {On March 11, 2020, Italy imposed a national lockdown to curtail the spread of severe acute respiratory syndrome coronavirus 2. We estimate that, 14 days after lockdown, the net reproduction number had dropped below 1 and remained stable at »0.76 (95% CI 0.67–0.85) in all regions for >3 of the following weeks.},
keywords = {COVID-19, Italy, lock-down, measures},
pubstate = {published},
tppubtype = {bachelorthesis}
}
On March 11, 2020, Italy imposed a national lockdown to curtail the spread of severe acute respiratory syndrome coronavirus 2. We estimate that, 14 days after lockdown, the net reproduction number had dropped below 1 and remained stable at »0.76 (95% CI 0.67–0.85) in all regions for >3 of the following weeks.
4.
Ruktanonchai, Nick Warren; Floyd, JR; Lai, Shengjie; Ruktanonchai, Corrine Warren; Sadilek, Adam; Rente-Lourenco, Pedro; Ben, Xue; Carioli, Alessandra; Gwinn, Joshua; Steele, JE; others,
Assessing the impact of coordinated COVID-19 exit strategies across Europe Journal Article
In: Science, vol. 369, no. 6510, pp. 1465–1470, 2020.
Abstract | Links | BibTeX | Tags: COVID-19, Europe, lock-down, measures, transmission
@article{ruktanonchai2020assessing,
title = {Assessing the impact of coordinated COVID-19 exit strategies across Europe},
author = {Nick Warren Ruktanonchai and JR Floyd and Shengjie Lai and Corrine Warren Ruktanonchai and Adam Sadilek and Pedro Rente-Lourenco and Xue Ben and Alessandra Carioli and Joshua Gwinn and JE Steele and others},
doi = {10.1126/science.abc5096},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
journal = {Science},
volume = {369},
number = {6510},
pages = {1465--1470},
publisher = {American Association for the Advancement of Science},
abstract = {As rates of new COVID-19 cases decline across Europe due to non-pharmaceutical interventions such as social distancing policies and lockdown measures, countries require guidance on how to ease restrictions while minimizing the risk of resurgent outbreaks. Here, we use mobility and case data to quantify how coordinated exit strategies could delay continental resurgence and limit community transmission of COVID-19. We find that a resurgent continental epidemic could occur as many as 5 weeks earlier when well-connected countries with stringent existing interventions end their interventions prematurely. Further, we found that appropriate coordination can greatly improve the likelihood of eliminating community transmission throughout Europe. In particular, synchronizing intermittent lockdowns across Europe meant half as many lockdown periods were required to end community transmission continent-wide.},
keywords = {COVID-19, Europe, lock-down, measures, transmission},
pubstate = {published},
tppubtype = {article}
}
As rates of new COVID-19 cases decline across Europe due to non-pharmaceutical interventions such as social distancing policies and lockdown measures, countries require guidance on how to ease restrictions while minimizing the risk of resurgent outbreaks. Here, we use mobility and case data to quantify how coordinated exit strategies could delay continental resurgence and limit community transmission of COVID-19. We find that a resurgent continental epidemic could occur as many as 5 weeks earlier when well-connected countries with stringent existing interventions end their interventions prematurely. Further, we found that appropriate coordination can greatly improve the likelihood of eliminating community transmission throughout Europe. In particular, synchronizing intermittent lockdowns across Europe meant half as many lockdown periods were required to end community transmission continent-wide.
3.
Pullano, Giulia; Valdano, Eugenio; Scarpa, Nicola; Rubrichi, Stefania; Colizza, Vittoria
In: The Lancet Digital Health, vol. 2, no. 12, pp. e638–e649, 2020.
Abstract | Links | BibTeX | Tags: big data, contac tracing, COVID-19, epidemiology, France, measures, mobility, transmission
@article{pullano2020evaluating,
title = {Evaluating the effect of demographic factors, socioeconomic factors, and risk aversion on mobility during the COVID-19 epidemic in France under lockdown: a population-based study},
author = {Giulia Pullano and Eugenio Valdano and Nicola Scarpa and Stefania Rubrichi and Vittoria Colizza},
doi = {10.1016/S2589-7500(20)30243-0 },
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
journal = {The Lancet Digital Health},
volume = {2},
number = {12},
pages = {e638--e649},
publisher = {Elsevier},
abstract = {Background: On March 17, 2020, French authorities implemented a nationwide lockdown to respond to the COVID-19 epidemic and curb the surge of patients requiring critical care. Assessing the effect of lockdown on individual displacements is essential to quantify achievable mobility reductions and identify the factors driving the changes in social dynamics that affected viral diffusion. We aimed to use mobile phone data to study how mobility in France changed before and during the lockdown, breaking down our findings by trip distance, user age and residency, and time of day, and analysing regional data and spatial heterogeneities. For this population-based study, we used temporally resolved travel flows among 1436 administrative areas of mainland France reconstructed from mobile phone trajectories. Data were stratified by age class (younger than 18 years, 18-64 years, and 65 years or older). We distinguished between residents and non-residents and used population data and regional socio-economic indicators from the French National Statistical Institute. We measured mobility changes before and during lockdown at both local and country scales using a case-crossover framework. We analysed all trips combined and trips longer than 100 km (termed long trips), and separated trips by daytime or night-time, weekdays or weekends, and rush hours.
Findings: Lockdown caused a 65% reduction in the countrywide number of displacements (from about 57 million to about 20 million trips per day) and was particularly effective in reducing work-related short-range mobility, especially during rush hour, and long trips. Geographical heterogeneities showed anomalous increases in long-range movements even before lockdown announcement that were tightly localised in space. During lockdown, mobility drops were unevenly distributed across regions (eg, Île-de-France, the region of Paris, went from 585 000 to 117 000 outgoing trips per day). They were strongly associated with active populations, workers employed in sectors highly affected by lockdown, and number of hospitalisations per region, and moderately associated with the socioeconomic level of the regions. Major cities largely shrank their pattern of connectivity, reducing it mainly to short-range commuting (95% of traffic leaving Paris was contained in a 201 km radius before lockdown, which was reduced to 29 km during lockdown).},
keywords = {big data, contac tracing, COVID-19, epidemiology, France, measures, mobility, transmission},
pubstate = {published},
tppubtype = {article}
}
Background: On March 17, 2020, French authorities implemented a nationwide lockdown to respond to the COVID-19 epidemic and curb the surge of patients requiring critical care. Assessing the effect of lockdown on individual displacements is essential to quantify achievable mobility reductions and identify the factors driving the changes in social dynamics that affected viral diffusion. We aimed to use mobile phone data to study how mobility in France changed before and during the lockdown, breaking down our findings by trip distance, user age and residency, and time of day, and analysing regional data and spatial heterogeneities. For this population-based study, we used temporally resolved travel flows among 1436 administrative areas of mainland France reconstructed from mobile phone trajectories. Data were stratified by age class (younger than 18 years, 18-64 years, and 65 years or older). We distinguished between residents and non-residents and used population data and regional socio-economic indicators from the French National Statistical Institute. We measured mobility changes before and during lockdown at both local and country scales using a case-crossover framework. We analysed all trips combined and trips longer than 100 km (termed long trips), and separated trips by daytime or night-time, weekdays or weekends, and rush hours.
Findings: Lockdown caused a 65% reduction in the countrywide number of displacements (from about 57 million to about 20 million trips per day) and was particularly effective in reducing work-related short-range mobility, especially during rush hour, and long trips. Geographical heterogeneities showed anomalous increases in long-range movements even before lockdown announcement that were tightly localised in space. During lockdown, mobility drops were unevenly distributed across regions (eg, Île-de-France, the region of Paris, went from 585 000 to 117 000 outgoing trips per day). They were strongly associated with active populations, workers employed in sectors highly affected by lockdown, and number of hospitalisations per region, and moderately associated with the socioeconomic level of the regions. Major cities largely shrank their pattern of connectivity, reducing it mainly to short-range commuting (95% of traffic leaving Paris was contained in a 201 km radius before lockdown, which was reduced to 29 km during lockdown).
Findings: Lockdown caused a 65% reduction in the countrywide number of displacements (from about 57 million to about 20 million trips per day) and was particularly effective in reducing work-related short-range mobility, especially during rush hour, and long trips. Geographical heterogeneities showed anomalous increases in long-range movements even before lockdown announcement that were tightly localised in space. During lockdown, mobility drops were unevenly distributed across regions (eg, Île-de-France, the region of Paris, went from 585 000 to 117 000 outgoing trips per day). They were strongly associated with active populations, workers employed in sectors highly affected by lockdown, and number of hospitalisations per region, and moderately associated with the socioeconomic level of the regions. Major cities largely shrank their pattern of connectivity, reducing it mainly to short-range commuting (95% of traffic leaving Paris was contained in a 201 km radius before lockdown, which was reduced to 29 km during lockdown).
2.
Candido, Darlan S; Claro, Ingra M; Jesus, Jaqueline G De; Souza, William M; Moreira, Filipe RR; Dellicour, Simon; Mellan, Thomas A; Plessis, Louis Du; Pereira, Rafael HM; Sales, Flavia CS; others,
Evolution and epidemic spread of SARS-CoV-2 in Brazil Journal Article
In: Science, vol. 369, no. 6508, pp. 1255–1260, 2020.
Abstract | Links | BibTeX | Tags: big data, Brazil, Contact tracing, COVID-19, epidemiology, measures, mobility, transmission
@article{candido2020evolution,
title = {Evolution and epidemic spread of SARS-CoV-2 in Brazil},
author = {Darlan S Candido and Ingra M Claro and Jaqueline G De Jesus and William M Souza and Filipe RR Moreira and Simon Dellicour and Thomas A Mellan and Louis Du Plessis and Rafael HM Pereira and Flavia CS Sales and others},
doi = {10.1126/science.abd2161},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
journal = {Science},
volume = {369},
number = {6508},
pages = {1255--1260},
publisher = {American Association for the Advancement of Science},
abstract = {Brazil currently has one of the fastest-growing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemics in the world. Because of limited available data, assessments of the impact of nonpharmaceutical interventions (NPIs) on this virus spread remain challenging. Using a mobility-driven transmission model, we show that NPIs reduced the reproduction number from >3 to 1 to 1.6 in São Paulo and Rio de Janeiro. Sequencing of 427 new genomes and analysis of a geographically representative genomic dataset identified >100 international virus introductions in Brazil. We estimate that most (76%) of the Brazilian strains fell in three clades that were introduced from Europe between 22 February and 11 March 2020. During the early epidemic phase, we found that SARS-CoV-2 spread mostly locally and within state borders. After this period, despite sharp decreases in air travel, we estimated multiple exportations from large urban centers that coincided with a 25% increase in average traveled distances in national flights. This study sheds new light on the epidemic transmission and evolutionary trajectories of SARS-CoV-2 lineages in Brazil and provides evidence that current interventions remain insufficient to keep virus transmission under control in this country.},
keywords = {big data, Brazil, Contact tracing, COVID-19, epidemiology, measures, mobility, transmission},
pubstate = {published},
tppubtype = {article}
}
Brazil currently has one of the fastest-growing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemics in the world. Because of limited available data, assessments of the impact of nonpharmaceutical interventions (NPIs) on this virus spread remain challenging. Using a mobility-driven transmission model, we show that NPIs reduced the reproduction number from >3 to 1 to 1.6 in São Paulo and Rio de Janeiro. Sequencing of 427 new genomes and analysis of a geographically representative genomic dataset identified >100 international virus introductions in Brazil. We estimate that most (76%) of the Brazilian strains fell in three clades that were introduced from Europe between 22 February and 11 March 2020. During the early epidemic phase, we found that SARS-CoV-2 spread mostly locally and within state borders. After this period, despite sharp decreases in air travel, we estimated multiple exportations from large urban centers that coincided with a 25% increase in average traveled distances in national flights. This study sheds new light on the epidemic transmission and evolutionary trajectories of SARS-CoV-2 lineages in Brazil and provides evidence that current interventions remain insufficient to keep virus transmission under control in this country.
1.
Chinazzi, Matteo; Davis, Jessica T; Ajelli, Marco; Gioannini, Corrado; Litvinova, Maria; Merler, Stefano; Piontti, Ana Pastore; Mu, Kunpeng; Rossi, Luca; Sun, Kaiyuan; others,
The effect of travel restrictions on the spread of the 2019 novel coronavirus (COVID-19) outbreak Journal Article
In: Science, vol. 368, no. 6489, pp. 395–400, 2020.
Abstract | Links | BibTeX | Tags: COVID-19, measures, mobility, Model, population dynamics
@article{chinazzi2020effect,
title = {The effect of travel restrictions on the spread of the 2019 novel coronavirus (COVID-19) outbreak},
author = {Matteo Chinazzi and Jessica T Davis and Marco Ajelli and Corrado Gioannini and Maria Litvinova and Stefano Merler and Ana Pastore Piontti and Kunpeng Mu and Luca Rossi and Kaiyuan Sun and others},
url = {https://www.science.org/doi/10.1126/science.aba9757},
doi = {10.1126/science.aba9757},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
journal = {Science},
volume = {368},
number = {6489},
pages = {395--400},
publisher = {American Association for the Advancement of Science},
abstract = {Motivated by the rapid spread of coronavirus disease 2019 (COVID-19) in mainland China, we use a global metapopulation disease transmission model to project the impact of travel limitations on the national and international spread of the epidemic. The model is calibrated on the basis of internationally reported cases and shows that, at the start of the travel ban from Wuhan on 23 January 2020, most Chinese cities had already received many infected travelers. The travel quarantine of Wuhan delayed the overall epidemic progression by only 3 to 5 days in mainland China but had a more marked effect on the international scale, where case importations were reduced by nearly 80% until mid-February. Modeling results also indicate that sustained 90% travel restrictions to and from mainland China only modestly affect the epidemic trajectory unless combined with a 50% or higher reduction of transmission in the community.},
keywords = {COVID-19, measures, mobility, Model, population dynamics},
pubstate = {published},
tppubtype = {article}
}
Motivated by the rapid spread of coronavirus disease 2019 (COVID-19) in mainland China, we use a global metapopulation disease transmission model to project the impact of travel limitations on the national and international spread of the epidemic. The model is calibrated on the basis of internationally reported cases and shows that, at the start of the travel ban from Wuhan on 23 January 2020, most Chinese cities had already received many infected travelers. The travel quarantine of Wuhan delayed the overall epidemic progression by only 3 to 5 days in mainland China but had a more marked effect on the international scale, where case importations were reduced by nearly 80% until mid-February. Modeling results also indicate that sustained 90% travel restrictions to and from mainland China only modestly affect the epidemic trajectory unless combined with a 50% or higher reduction of transmission in the community.