Population mobility reductions associated with travel restrictions during the Ebola epidemic in Sierra Leone: use of mobile phone data
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Open Access
- 1 October 2018
- journal article
- research article
- Published by Oxford University Press (OUP) in International Journal of Epidemiology
- Vol. 47 (5), 1562-1570
- https://doi.org/10.1093/ije/dyy095
Abstract
Background: Travel restrictions were implemented on an unprecedented scale in 2015 in Sierra Leone to contain and eliminate Ebola virus disease. However, the impact of epidemic travel restrictions on mobility itself remains difficult to measure with traditional methods. New 'big data' approaches using mobile phone data can provide, in near real-time, the type of information needed to guide and evaluate control measures. Methods: We analysed anonymous mobile phone call detail records (CDRs) from a leading operator in Sierra Leone between 20 March and 1 July in 2015. We used an anomaly detection algorithm to assess changes in travel during a national 'stay at home' lockdown from 27 to 29 March. To measure the magnitude of these changes and to assess effect modification by region and historical Ebola burden, we performed a time series analysis and a crossover analysis. Results: Routinely collected mobile phone data revealed a dramatic reduction in human mobility during a 3-day lockdown in Sierra Leone. The number of individuals relocating between chiefdoms decreased by 31% within 15 km, by 46% for 15-30 km and by 76% for distances greater than 30 km. This effect was highly heterogeneous in space, with higher impact in regions with higher Ebola incidence. Travel quickly returned to normal patterns after the restrictions were lifted. Conclusions: The effects of travel restrictions on mobility can be large, targeted and measurable in near real-time. With appropriate anonymization protocols, mobile phone data should play a central role in guiding and monitoring interventions for epidemic containment.Funding Information
- National Institute of General Medical Sciences (U54GM088558)
- National Research Service Award (T32AI007535–16A)
- Wellcome Trust Sustaining Health (106866/Z/15/Z)
- Swedish Research Council (D0313701)
- Burroughs Wellcome Fund
- Natural Science Foundation of China (71522014)
- National Institute of General Medical Sciences
- National Institutes of Health
This publication has 27 references indexed in Scilit:
- Ebola: Mobility dataScience, 2014
- Assessing the impact of travel restrictions on international spread of the 2014 West African Ebola epidemicEurosurveillance, 2014
- Lessons from the History of Quarantine, from Plague to Influenza AEmerging Infectious Diseases, 2013
- Public response to the 2009 influenza A H1N1 pandemic: a polling study in five countriesThe Lancet Infectious Diseases, 2012
- Improved Response to Disasters and Outbreaks by Tracking Population Movements with Mobile Phone Network Data: A Post-Earthquake Geospatial Study in HaitiPLoS Medicine, 2011
- Human Mobility Networks, Travel Restrictions, and the Global Spread of 2009 H1N1 PandemicPLOS ONE, 2011
- Non-Pharmaceutical Interventions during an Outbreak of 2009 Pandemic Influenza A (H1N1) Virus Infection at a Large Public University, April-May 2009Clinical Infectious Diseases, 2010
- Multiscale mobility networks and the spatial spreading of infectious diseasesProceedings of the National Academy of Sciences of the United States of America, 2009
- Air Travel and the Spread of Influenza: Important CaveatsPLoS Medicine, 2006
- Empirical Evidence for the Effect of Airline Travel on Inter-Regional Influenza Spread in the United StatesPLoS Medicine, 2006