Skip to main content

Spatial Transmission of 2009 Pandemic Influenza in the US

Author(s): Gog, Julia R.; Ballesteros, Sébastien; Viboud, Cécile; Simonsen, Lone; Bjørnstad, Ottar N.; et al

To refer to this page use:
Abstract: The 2009 H1N1 influenza pandemic provides a unique opportunity for detailed examination of the spatial dynamics of an emerging pathogen. In the US, the pandemic was characterized by substantial geographical heterogeneity: the 2009 spring wave was limited mainly to northeastern cities while the larger fall wave affected the whole country. Here we use finely resolved spatial and temporal influenza disease data based on electronic medical claims to explore the spread of the fall pandemic wave across 271 US cities and associated suburban areas. We document a clear spatial pattern in the timing of onset of the fall wave, starting in southeastern cities and spreading outwards over a period of three months. We use mechanistic models to tease apart the external factors associated with the timing of the fall wave arrival: differential seeding events linked to demographic factors, school opening dates, absolute humidity, prior immunity from the spring wave, spatial diffusion, and their interactions. Although the onset of the fall wave was correlated with school openings as previously reported, models including spatial spread alone resulted in better fit. The best model had a combination of the two. Absolute humidity or prior exposure during the spring wave did not improve the fit and population size only played a weak role. In conclusion, the protracted spread of pandemic influenza in fall 2009 in the US was dominated by short-distance spatial spread partially catalysed by school openings rather than long-distance transmission events. This is in contrast to the rapid hierarchical transmission patterns previously described for seasonal influenza. The findings underline the critical role that school-age children play in facilitating the geographic spread of pandemic influenza and highlight the need for further information on the movement and mixing patterns of this age group.
Publication Date: 12-Jun-2014
Electronic Publication Date: 12-Jun-2014
Citation: Gog, Julia R., Ballesteros, Sébastien, Viboud, Cécile, Simonsen, Lone, Bjornstad, Ottar N., Shaman, Jeffrey, Chao, Dennis L., Khan, Farid, Grenfell, Bryan T. (2014). Spatial Transmission of 2009 Pandemic Influenza in the US. PLoS Computational Biology, 10 (6), e1003635 - e1003635. doi:10.1371/journal.pcbi.1003635
DOI: doi:10.1371/journal.pcbi.1003635
EISSN: 1553-7358
Pages: e1003635 - e1003635
Type of Material: Journal Article
Journal/Proceeding Title: PLoS Computational Biology
Version: Final published version. This is an open access article.

Items in OAR@Princeton are protected by copyright, with all rights reserved, unless otherwise indicated.