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Influenza Other Respir Viruses. 2019 Nov 9. doi: 10.1111/irv.12690. [Epub ahead of print] Flying, phones and flu: Anonymized call records suggest that Keflavik International Airport introduced pandemic H1N1 into Iceland in 2009.
Kishore N1, Mitchell R2,3, Lash TL4, Reed C5, Danon L6,7, Sigmundsd?ttir G8, Vigfusson Y2,9.
Author information
1 Department of Epidemiology, T.H. Chan School of Public Health, Harvard University, Boston, MA, USA. 2 Department of Computer Science, Emory University, Atlanta, GA, USA. 3 Nell Hodgson Woodruff School of Nursing, Emory University, Atlanta, GA, USA. 4 Department of Epidemiology, Rollins School of Public Health, Atlanta, GA, USA. 5 Epidemiology and Prevention Branch, Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA. 6 College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK. 7 Alan Turing Institute, British Library, London, UK. 8 Centre for Health Security and Communicable Disease Center Control, Directorate of Health of Iceland, Reykjav?k, Iceland. 9 School of Computer Science, Reykjav?k University, Reykjav?k, Iceland.
Abstract
BACKGROUND:
Data collected by mobile devices can augment surveillance of epidemics in real time. However, methods and evidence for the integration of these data into modern surveillance systems are sparse. We linked call detail records (CDR) with an influenza-like illness (ILI) registry and evaluated the role that Icelandic international travellers played in the introduction and propagation of influenza A/H1N1pdm09 virus in Iceland through the course of the 2009 pandemic.
METHODS:
This nested case-control study compared odds of exposure to Keflavik International Airport among cases and matched controls producing longitudinal two-week matched odds ratios (mORs) from August to December 2009. We further evaluated rates of ILI among 1st- and 2nd-degree phone connections of cases compared to their matched controls.
RESULTS:
The mOR was elevated in the initial stages of the epidemic from 7 August until 21 August (mOR = 2.53; 95% confidence interval (CI) = 1.35, 4.78). During the two-week period from 17 August through 31 August, we calculated the two-week incidence density ratio of ILI among 1st-degree connections to be 2.96 (95% CI: 1.43, 5.84).
CONCLUSIONS:
Exposure to Keflavik International Airport increased the risk of incident ILI diagnoses during the initial stages of the epidemic. Using these methods for other regions of Iceland, we evaluated the geographic spread of ILI over the course of the epidemic. Our methods were validated through similar evaluation of a domestic airport. The techniques described in this study can be used for hypothesis-driven evaluations of locations and behaviours during an epidemic and their associations with health outcomes.
? 2019 The Authors. Influenza and Other Respiratory Viruses published by John Wiley & Sons Ltd.
KEYWORDS:
Iceland; big data; call detail records; case-control studies; influenza; pandemics
PMID: 31705633 DOI: 10.1111/irv.12690
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