Total: 126
Examining the correlates and drivers of human population distributions across low- and middle-income countries
Journal of the Royal Society Interface, Volume 14, issue 137 (2017).
Author(s): Jeremiah J. Nieves, Forrest R. Stevens, Andrea E. Gaughan, Catherine Linard, Alessandro Sorichetta, Graeme Hornby, Nirav N. Patel, Andrew J. Tatem.
Type: method. Year: 2017
DOI: 10.1098/rsif.2017.0401.

Abstract: Geographical factors have influenced the distributions and densities of global human population distributions for centuries. Climatic regimes have made some regions more habitable than others, harsh topography has discouraged human settlement, and transport links have encouraged population growth. A better understanding of these types of relationships enables both improved mapping of population distributions today and modelling of future scenarios. However, few comprehensive studies of the relationships between population spatial distributions and the range of drivers and correlates that exist have been undertaken at all, much less at high spatial resolutions, and particularly across the low- and middle-income countries. Here, we quantify the relative importance of multiple types of drivers and covariates in explaining observed population densities across 32 low- and middle-income countries over four continents using machine-learning approaches. We find that, while relationships between population densities and geographical factors show some variation between regions, they are generally remarkably consistent, pointing to universal drivers of human population distribution. Here, we find that a set of geographical features relating to the built environment, ecology and topography consistently explain the majority of variability in population distributions at fine spatial scales across the low- and middle-income regions of the world.
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Multinational patterns of seasonal asymmetry in human movement influence infectious disease dynamics
Nature Communications 8, Article number: 2069 (2017) .
Author(s): Amy Wesolowski, Elisabeth zu Erbach-Schoenberg, Andrew J. Tatem, Christopher Lourenço, Cecile Viboud, Vivek Charu, Nathan Eagle, Kenth Engø-Monsen, Taimur Qureshi, Caroline O. Buckee & C. J. E. Metcalf
Type: method. Year: 2017
DOI: 10.1038/s41467-017-02064-4.

Abstract: Seasonal variation in human mobility is globally ubiquitous and affects the spatial spread of infectious diseases, but the ability to measure seasonality in human movement has been limited by data availability. Here, we use mobile phone data to quantify seasonal travel and directional asymmetries in Kenya, Namibia, and Pakistan, across a spectrum from rural nomadic populations to highly urbanized communities. We then model how the geographic spread of several acute pathogens with varying life histories could depend on country-wide connectivity fluctuations through the year. In all three countries, major national holidays are associated with shifts in the scope of travel. Within this broader pattern, the relative importance of particular routes also fluctuates over the course of the year, with increased travel from rural to urban communities after national holidays, for example. These changes in travel impact how fast communities are likely to be reached by an introduced pathogen.
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Housing Improvements and Malaria Risk in Sub-Saharan Africa: A Multi-Country Analysis of Survey Data.
PLOS Medicine. 2017. .
Author(s): Lucy S. Tusting , Christian Bottomley, Harry Gibson, Immo Kleinschmidt, Andrew J. Tatem, Steve W. Lindsay, Peter W. Gething.
Type: application. Year: 2017
DOI: 10.1371/journal.pmed.1002234.

Abstract: Improvements to housing may contribute to malaria control and elimination by reducing house entry by malaria vectors and thus exposure to biting. We tested the hypothesis that the odds of malaria infection are lower in modern, improved housing compared to traditional housing in sub-Saharan Africa (SSA).
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Virus genomes reveal factors that spread and sustained the Ebola epidemic.
Nature 544, 309–315 (20 April 2017).
Author(s): Gytis Dudas, Luiz Max Carvalho, Trevor Bedford, Andrew J. Tatem, Guy Baele, Nuno R. Faria, Daniel J. Park, Jason T. Ladner, Armando Arias, Danny Asogun, Filip Bielejec, Sarah L. Caddy, Matthew Cotten, Jonathan D'Ambrozio, Simon Dellicour, Antonino Di Caro, Joseph W. Diclaro, Sophie Duraffour, Michael J. Elmore, Lawrence S. Fakoli, Ousmane Faye, Merle L. Gilbert, Sahr M. Gevao, Stephen Gire, Adrianne Gladden-Young
Type: application. Year: 2017
DOI: 10.1038/nature22040.

Abstract: The 2013–2016 West African epidemic caused by the Ebola virus was of unprecedented magnitude, duration and impact. Here we reconstruct the dispersal, proliferation and decline of Ebola virus throughout the region by analysing 1,610 Ebola virus genomes, which represent over 5% of the known cases. We test the association of geography, climate and demography with viral movement among administrative regions, inferring a classic 'gravity' model, with intense dispersal between larger and closer populations. Despite attenuation of international dispersal after border closures, cross-border transmission had already sown the seeds for an international epidemic, rendering these measures ineffective at curbing the epidemic. We address why the epidemic did not spread into neighbouring countries, showing that these countries were susceptible to substantial outbreaks but at lower risk of introductions. Finally, we reveal that this large epidemic was a heterogeneous and spatially dissociated collection of transmission clusters of varying size, duration and connectivity. These insights will help to inform interventions in future epidemics
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