Publications
Wardrop, N. A.; Jochem, W. C.; Bird, T. J.; Chamberlain, H. R.; Clarke, D.; Kerr, D.; Bengtsson, L.; Juran, S.; Seaman, V.; Tatem, A. J.
Spatially disaggregated population estimates in the absence of national population and housing census data Journal Article
In: Proceedings of the National Academy of Sciences, vol. 115, no. 14, pp. 3529-3537, 2018.
Abstract | Links | BibTeX | Tags:
@article{doi:10.1073/pnas.1715305115,
title = {Spatially disaggregated population estimates in the absence of national population and housing census data},
author = {N. A. Wardrop and W. C. Jochem and T. J. Bird and H. R. Chamberlain and D. Clarke and D. Kerr and L. Bengtsson and S. Juran and V. Seaman and A. J. Tatem},
url = {https://www.pnas.org/doi/abs/10.1073/pnas.1715305115},
doi = {10.1073/pnas.1715305115},
year = {2018},
date = {2018-01-01},
journal = {Proceedings of the National Academy of Sciences},
volume = {115},
number = {14},
pages = {3529-3537},
abstract = {Population numbers at local levels are fundamental data for many applications, including the delivery and planning of services, election preparation, and response to disasters. In resource-poor settings, recent and reliable demographic data at subnational scales can often be lacking. National population and housing census data can be outdated, inaccurate, or missing key groups or areas, while registry data are generally lacking or incomplete. Moreover, at local scales accurate boundary data are often limited, and high rates of migration and urban growth make existing data quickly outdated. Here we review past and ongoing work aimed at producing spatially disaggregated local-scale population estimates, and discuss how new technologies are now enabling robust and cost-effective solutions. Recent advances in the availability of detailed satellite imagery, geopositioning tools for field surveys, statistical methods, and computational power are enabling the development and application of approaches that can estimate population distributions at fine spatial scales across entire countries in the absence of census data. We outline the potential of such approaches as well as their limitations, emphasizing the political and operational hurdles for acceptance and sustainable implementation of new approaches, and the continued importance of traditional sources of national statistical data.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Wesolowski, Amy; Winter, Amy; Tatem, Andrew J.; Qureshi, Taimur; Engø-Monsen, Kenth; Buckee, Caroline O.; Cummings, Derek A. T.; Metcalf, C. Jessica E.
In: Epidemiology and Infection, vol. 146, no. 12, pp. 1575–1583, 2018.
@article{wesolowski_winter_tatem_qureshi_engø-monsen_buckee_cummings_metcalf_2018,
title = {Measles outbreak risk in Pakistan: exploring the potential of combining vaccination coverage and incidence data with novel data-streams to strengthen control},
author = {Amy Wesolowski and Amy Winter and Andrew J. Tatem and Taimur Qureshi and Kenth Engø-Monsen and Caroline O. Buckee and Derek A. T. Cummings and C. Jessica E. Metcalf},
doi = {10.1017/S0950268818001449},
year = {2018},
date = {2018-01-01},
journal = {Epidemiology and Infection},
volume = {146},
number = {12},
pages = {1575–1583},
publisher = {Cambridge University Press},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Zagatti, Guilherme Augusto; Gonzalez, Miguel; Avner, Paolo; Lozano-Gracia, Nancy; Brooks, Christopher J.; Albert, Maximilian; Gray, Jonathan; Antos, Sarah Elizabeth; Burci, Priya; Erbach-Schoenberg, Elisabeth; Tatem, Andrew J.; Wetter, Erik; Bengtsson, Linus
A trip to work: Estimation of origin and destination of commuting patterns in the main metropolitan regions of Haiti using CDR Journal Article
In: Development Engineering, vol. 3, pp. 133-165, 2018, ISSN: 2352-7285.
Abstract | Links | BibTeX | Tags: Call detail records, CDR, Commuting, Non-supervised learning, Urban planning, Urbanisation
@article{ZAGATTI2018133,
title = {A trip to work: Estimation of origin and destination of commuting patterns in the main metropolitan regions of Haiti using CDR},
author = {Guilherme Augusto Zagatti and Miguel Gonzalez and Paolo Avner and Nancy Lozano-Gracia and Christopher J. Brooks and Maximilian Albert and Jonathan Gray and Sarah Elizabeth Antos and Priya Burci and Elisabeth Erbach-Schoenberg and Andrew J. Tatem and Erik Wetter and Linus Bengtsson},
url = {https://www.sciencedirect.com/science/article/pii/S2352728517300866},
doi = {https://doi.org/10.1016/j.deveng.2018.03.002},
issn = {2352-7285},
year = {2018},
date = {2018-01-01},
journal = {Development Engineering},
volume = {3},
pages = {133-165},
abstract = {The rapid, unplanned urbanisation in Haiti creates a series of urban mobility challenges which can contribute to job market fragmentation and decrease the quality of life in the city. Data on population and job distributions, and on home-work commuting patterns in major urban centres are scarce. The most recent census took place in 2003 and events such as the 2010 earthquake have caused major redistributions of the population. In this data scarce context, our work takes advantage of nationwide de-identified Call Detail Records (CDR) from the main mobile operator in the country to investigate night and daytime populations densities and commuting patterns. We use a non-supervised learning algorithm to identify meaningful locations for individuals. These locations are then labelled according to a scoring criteria. The labelled locations are distributed in a grid with cells measuring 500 × 500 m in order to aggregate the individual level data and to create origin-destination matrices of weighted connections between home and work locations. The results suggest that labor markets are fragmented in Haiti. The two main urban centres, Port-au-Prince and Cap-Haïtien suffer from low employment accessibility as measured by the percentage of the population that travels beyond their identified home cluster (1 km radius) during the day. The data from the origin-destination matrices suggest that only 42 and 40 percent of the population are considered to be commuters in Port-au-Prince and Cap-Haïtien respectively.},
keywords = {Call detail records, CDR, Commuting, Non-supervised learning, Urban planning, Urbanisation},
pubstate = {published},
tppubtype = {article}
}
Reed, Fennis J.; Gaughan, Andrea E.; Stevens, Forrest R.; Yetman, Greg; Sorichetta, Alessandro; Tatem, Andrew J.
Gridded Population Maps Informed by Different Built Settlement Products Journal Article
In: Data, vol. 3, no. 3, 2018, ISSN: 2306-5729.
Abstract | Links | BibTeX | Tags:
@article{data3030033,
title = {Gridded Population Maps Informed by Different Built Settlement Products},
author = {Fennis J. Reed and Andrea E. Gaughan and Forrest R. Stevens and Greg Yetman and Alessandro Sorichetta and Andrew J. Tatem},
url = {https://www.mdpi.com/2306-5729/3/3/33},
doi = {10.3390/data3030033},
issn = {2306-5729},
year = {2018},
date = {2018-01-01},
journal = {Data},
volume = {3},
number = {3},
abstract = {The spatial distribution of humans on the earth is critical knowledge that informs many disciplines and is available in a spatially explicit manner through gridded population techniques. While many approaches exist to produce specialized gridded population maps, little has been done to explore how remotely sensed, built-area datasets might be used to dasymetrically constrain these estimates. This study presents the effectiveness of three different high-resolution built area datasets for producing gridded population estimates through the dasymetric disaggregation of census counts in Haiti, Malawi, Madagascar, Nepal, Rwanda, and Thailand. Modeling techniques include a binary dasymetric redistribution, a random forest with a dasymetric component, and a hybrid of the previous two. The relative merits of these approaches and the data are discussed with regards to studying human populations and related spatially explicit phenomena. Results showed that the accuracy of random forest and hybrid models was comparable in five of six countries.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Lai, Shengjie; Johansson, Michael A.; Yin, Wenwu; Wardrop, Nicola A.; Panhuis, Willem G.; Wesolowski, Amy; Kraemer, Moritz U. G.; Bogoch, Isaac I.; Kain, Dylain; Findlater, Aidan; Choisy, Marc; Huang, Zhuojie; Mu, Di; Li, Yu; He, Yangni; Chen, Qiulan; Yang, Juan; Khan, Kamran; Tatem, Andrew J.; Yu, Hongjie
Seasonal and interannual risks of dengue introduction from South-East Asia into China, 2005-2015 Journal Article
In: PLOS Neglected Tropical Diseases, vol. 12, no. 11, pp. 1-16, 2018.
Abstract | Links | BibTeX | Tags:
@article{10.1371/journal.pntd.0006743,
title = {Seasonal and interannual risks of dengue introduction from South-East Asia into China, 2005-2015},
author = {Shengjie Lai and Michael A. Johansson and Wenwu Yin and Nicola A. Wardrop and Willem G. Panhuis and Amy Wesolowski and Moritz U. G. Kraemer and Isaac I. Bogoch and Dylain Kain and Aidan Findlater and Marc Choisy and Zhuojie Huang and Di Mu and Yu Li and Yangni He and Qiulan Chen and Juan Yang and Kamran Khan and Andrew J. Tatem and Hongjie Yu},
url = {https://doi.org/10.1371/journal.pntd.0006743},
doi = {10.1371/journal.pntd.0006743},
year = {2018},
date = {2018-01-01},
journal = {PLOS Neglected Tropical Diseases},
volume = {12},
number = {11},
pages = {1-16},
publisher = {Public Library of Science},
abstract = {Due to worldwide increased human mobility, air-transportation data and mathematical models have been widely used to measure risks of global dispersal of pathogens. However, the seasonal and interannual risks of pathogens importation and onward transmission from endemic countries have rarely been quantified and validated. We constructed a modelling framework, integrating air travel, epidemiological, demographical, entomological and meteorological data, to measure the seasonal probability of dengue introduction from endemic countries. This framework has been applied retrospectively to elucidate spatiotemporal patterns and increasing seasonal risk of dengue importation from South-East Asia into China via air travel in multiple populations, Chinese travelers and local residents, over a decade of 2005–15. We found that the volume of airline travelers from South-East Asia into China has quadrupled from 2005 to 2015 with Chinese travelers increased rapidly. Following the growth of air traffic, the probability of dengue importation from South-East Asia into China has increased dramatically from 2005 to 2015. This study also revealed seasonal asymmetries of transmission routes: Sri Lanka and Maldives have emerged as origins; neglected cities at central and coastal China have been increasingly vulnerable to dengue importation and onward transmission. Compared to the monthly occurrence of dengue reported in China, our model performed robustly for importation and onward transmission risk estimates. The approach and evidence could facilitate to understand and mitigate the changing seasonal threat of arbovirus from endemic regions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Ouma, Paul O; Maina, Joseph; Thuranira, Pamela N; Macharia, Peter M; Alegana, Victor A; English, Mike; Okiro, Emelda A; Snow, Robert W
Access to emergency hospital care provided by the public sector in sub-Saharan Africa in 2015: a geocoded inventory and spatial analysis Journal Article
In: The Lancet Global Health, vol. 6, no. 3, pp. e342-e350, 2018, ISSN: 2214-109X.
Abstract | Links | BibTeX | Tags:
@article{OUMA2018e342,
title = {Access to emergency hospital care provided by the public sector in sub-Saharan Africa in 2015: a geocoded inventory and spatial analysis},
author = {Paul O Ouma and Joseph Maina and Pamela N Thuranira and Peter M Macharia and Victor A Alegana and Mike English and Emelda A Okiro and Robert W Snow},
url = {https://www.sciencedirect.com/science/article/pii/S2214109X17304886},
doi = {https://doi.org/10.1016/S2214-109X(17)30488-6},
issn = {2214-109X},
year = {2018},
date = {2018-01-01},
journal = {The Lancet Global Health},
volume = {6},
number = {3},
pages = {e342-e350},
abstract = {Summary
Background
Timely access to emergency care can substantially reduce mortality. International benchmarks for access to emergency hospital care have been established to guide ambitions for universal health care by 2030. However, no Pan-African database of where hospitals are located exists; therefore, we aimed to complete a geocoded inventory of hospital services in Africa in relation to how populations might access these services in 2015, with focus on women of child bearing age.
Methods
We assembled a geocoded inventory of public hospitals across 48 countries and islands of sub-Saharan Africa, including Zanzibar, using data from various sources. We only included public hospitals with emergency services that were managed by governments at national or local levels and faith-based or non-governmental organisations. For hospital listings without geographical coordinates, we geocoded each facility using Microsoft Encarta (version 2009), Google Earth (version 7.3), Geonames, Fallingrain, OpenStreetMap, and other national digital gazetteers. We obtained estimates for total population and women of child bearing age (15–49 years) at a 1 km2 spatial resolution from the WorldPop database for 2015. Additionally, we assembled road network data from Google Map Maker Project and OpenStreetMap using ArcMap (version 10.5). We then combined the road network and the population locations to form a travel impedance surface. Subsequently, we formulated a cost distance algorithm based on the location of public hospitals and the travel impedance surface in AccessMod (version 5) to compute the proportion of populations living within a combined walking and motorised travel time of 2 h to emergency hospital services.
Findings
We consulted 100 databases from 48 sub-Saharan countries and islands, including Zanzibar, and identified 4908 public hospitals. 2701 hospitals had either full or partial information about their geographical coordinates. We estimated that 287 282 013 (29·0%) people and 64 495 526 (28·2%) women of child bearing age are located more than 2-h travel time from the nearest hospital. Marked differences were observed within and between countries, ranging from less than 25% of the population within 2-h travel time of a public hospital in South Sudan to more than 90% in Nigeria, Kenya, Cape Verde, Swaziland, South Africa, Burundi, Comoros, São Tomé and Príncipe, and Zanzibar. Only 16 countries reached the international benchmark of more than 80% of their populations living within a 2-h travel time of the nearest hospital.
Interpretation
Physical access to emergency hospital care provided by the public sector in Africa remains poor and varies substantially within and between countries. Innovative targeting of emergency care services is necessary to reduce these inequities. This study provides the first spatial census of public hospital services in Africa.
Funding
Wellcome Trust and the UK Department for International Development.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background
Timely access to emergency care can substantially reduce mortality. International benchmarks for access to emergency hospital care have been established to guide ambitions for universal health care by 2030. However, no Pan-African database of where hospitals are located exists; therefore, we aimed to complete a geocoded inventory of hospital services in Africa in relation to how populations might access these services in 2015, with focus on women of child bearing age.
Methods
We assembled a geocoded inventory of public hospitals across 48 countries and islands of sub-Saharan Africa, including Zanzibar, using data from various sources. We only included public hospitals with emergency services that were managed by governments at national or local levels and faith-based or non-governmental organisations. For hospital listings without geographical coordinates, we geocoded each facility using Microsoft Encarta (version 2009), Google Earth (version 7.3), Geonames, Fallingrain, OpenStreetMap, and other national digital gazetteers. We obtained estimates for total population and women of child bearing age (15–49 years) at a 1 km2 spatial resolution from the WorldPop database for 2015. Additionally, we assembled road network data from Google Map Maker Project and OpenStreetMap using ArcMap (version 10.5). We then combined the road network and the population locations to form a travel impedance surface. Subsequently, we formulated a cost distance algorithm based on the location of public hospitals and the travel impedance surface in AccessMod (version 5) to compute the proportion of populations living within a combined walking and motorised travel time of 2 h to emergency hospital services.
Findings
We consulted 100 databases from 48 sub-Saharan countries and islands, including Zanzibar, and identified 4908 public hospitals. 2701 hospitals had either full or partial information about their geographical coordinates. We estimated that 287 282 013 (29·0%) people and 64 495 526 (28·2%) women of child bearing age are located more than 2-h travel time from the nearest hospital. Marked differences were observed within and between countries, ranging from less than 25% of the population within 2-h travel time of a public hospital in South Sudan to more than 90% in Nigeria, Kenya, Cape Verde, Swaziland, South Africa, Burundi, Comoros, São Tomé and Príncipe, and Zanzibar. Only 16 countries reached the international benchmark of more than 80% of their populations living within a 2-h travel time of the nearest hospital.
Interpretation
Physical access to emergency hospital care provided by the public sector in Africa remains poor and varies substantially within and between countries. Innovative targeting of emergency care services is necessary to reduce these inequities. This study provides the first spatial census of public hospital services in Africa.
Funding
Wellcome Trust and the UK Department for International Development.
Utazi, C Edson; Sahu, Sujit K; Atkinson, Peter M; Tejedor-Garavito, Natalia; Lloyd, Christopher T; Tatem, Andrew J
Geographic coverage of demographic surveillance systems for characterising the drivers of childhood mortality in sub-Saharan Africa Journal Article
In: BMJ Global Health, vol. 3, no. 2, 2018.
Abstract | Links | BibTeX | Tags:
@article{Utazie000611,
title = {Geographic coverage of demographic surveillance systems for characterising the drivers of childhood mortality in sub-Saharan Africa},
author = {C Edson Utazi and Sujit K Sahu and Peter M Atkinson and Natalia Tejedor-Garavito and Christopher T Lloyd and Andrew J Tatem},
url = {https://gh.bmj.com/content/3/2/e000611},
doi = {10.1136/bmjgh-2017-000611},
year = {2018},
date = {2018-01-01},
journal = {BMJ Global Health},
volume = {3},
number = {2},
publisher = {BMJ Specialist Journals},
abstract = {A major focus of international health and development goals is the reduction of mortality rates in children under 5 years of age. Achieving this requires understanding the drivers of mortality and how they vary geographically to facilitate the targeting and prioritisation of appropriate interventions. Much of our knowledge on the causes of, and trends in, childhood mortality come from longitudinal demographic surveillance sites, with a renewed focus recently on the establishment and growth of networks of sites from which standardised outputs can facilitate broader understanding of processes. To ensure that the collective outputs from surveillance sites can be used to derive a comprehensive understanding and monitoring system for driving policy on tackling childhood mortality, confidence is needed that existing and planned networks of sites are providing a reliable and representative picture of the geographical variation in factors associated with mortality. Here, we assembled subnational data on childhood mortality as well as key factors known to be associated with it from household surveys in 27 sub-Saharan African countries. We then mapped the locations of existing longitudinal demographic surveillance sites to assess the extent of current coverage of the range of factors, identifying where gaps exist. The results highlight regions with unique combinations of factors associated with childhood mortality that are poorly represented by the current distribution of sites, such as southern Mali, central Nigeria and southern Zambia. Finally, we determined where the establishment of new surveillance systems could improve coverage.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Juran, Sabrina; Broer, P. Niclas; Klug, Stefanie J.; Snow, Rachel C.; Okiro, Emelda A.; Ouma, Paul O.; Snow, Robert W.; Tatem, Andrew J.; Meara, John G.; Alegana, Victor A.
Geospatial mapping of access to timely essential surgery in sub-Saharan Africa Journal Article
In: BMJ Global Health, vol. 3, no. 4, 2018.
Abstract | Links | BibTeX | Tags:
@article{Jurane000875,
title = {Geospatial mapping of access to timely essential surgery in sub-Saharan Africa},
author = {Sabrina Juran and P. Niclas Broer and Stefanie J. Klug and Rachel C. Snow and Emelda A. Okiro and Paul O. Ouma and Robert W. Snow and Andrew J. Tatem and John G. Meara and Victor A. Alegana},
url = {https://gh.bmj.com/content/3/4/e000875},
doi = {10.1136/bmjgh-2018-000875},
year = {2018},
date = {2018-01-01},
journal = {BMJ Global Health},
volume = {3},
number = {4},
publisher = {BMJ Specialist Journals},
abstract = {Introduction Despite an estimated one-third of the global burden of disease being surgical, only limited estimates of accessibility to surgical treatment in sub-Saharan Africa exist and these remain spatially undefined. Geographical metrics of access to major hospitals were estimated based on travel time. Estimates were then used to assess need for surgery at country level.Methods Major district and regional hospitals were assumed to have capability to perform bellwether procedures. Geographical locations of hospitals in relation to the population in the 47 sub-Saharan countries were combined with spatial ancillary data on roads, elevation, land use or land cover to estimate travel-time metrics of 30 min, 1 hour and 2 hours. Hospital catchment was defined as population residing in areas less than 2 hours of travel time to the next major hospital. Travel-time metrics were combined with fine-scale population maps to define burden of surgery at hospital catchment level.Results Overall, the majority of the population (92.5%) in sub-Saharan Africa reside in areas within 2 hours of a major hospital catchment defined based on spatially defined travel times. The burden of surgery in all-age population was 257.8 million to 294.7 million people and was highest in high-population density countries and lowest in sparsely populated or smaller countries. The estimated burden in children <15 years was 115.3 million to 131.8 million and had similar spatial distribution to the all-age pattern.Conclusion The study provides an assessment of accessibility and burden of surgical disease in sub-Saharan Africa. Yet given the optimistic assumption of adequare surgical capability of major hospitals, the true burden of surgical disease is expected to be much greater. In-depth health facility assessments are needed to define infrastructure, personnel and medicine supply for delivering timely and safe affordable surgery to further inform the analysis.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Weber, Eric M.; Seaman, Vincent Y.; Stewart, Robert N.; Bird, Tomas J.; Tatem, Andrew J.; McKee, Jacob J.; Bhaduri, Budhendra L.; Moehl, Jessica J.; Reith, Andrew E.
Census-independent population mapping in northern Nigeria Journal Article
In: Remote Sensing of Environment, vol. 204, pp. 786-798, 2018, ISSN: 0034-4257.
Abstract | Links | BibTeX | Tags: Demographics, Nigeria, Polio, Population, Settlement mapping
@article{WEBER2018786,
title = {Census-independent population mapping in northern Nigeria},
author = {Eric M. Weber and Vincent Y. Seaman and Robert N. Stewart and Tomas J. Bird and Andrew J. Tatem and Jacob J. McKee and Budhendra L. Bhaduri and Jessica J. Moehl and Andrew E. Reith},
url = {https://www.sciencedirect.com/science/article/pii/S0034425717304364},
doi = {https://doi.org/10.1016/j.rse.2017.09.024},
issn = {0034-4257},
year = {2018},
date = {2018-01-01},
journal = {Remote Sensing of Environment},
volume = {204},
pages = {786-798},
abstract = {Although remote sensing has long been used to aid in the estimation of population, it has usually been in the context of spatial disaggregation of national census data, with the census counts serving both as observational data for specifying models and as constraints on model outputs. Here we present a framework for estimating populations from the bottom up, entirely independently of national census data, a critical need in areas without recent and reliable census data. To make observations of population density, we replace national census data with a microcensus, in which we enumerate population for a sample of small areas within the states of Kano and Kaduna in northern Nigeria. Using supervised texture-based classifiers with very high resolution satellite imagery, we produce a binary map of human settlement at 8-meter resolution across the two states and then a more refined classification consisting of 7 residential types and 1 non-residential type. Using the residential types and a model linking them to the population density observations, we produce population estimates across the two states in a gridded raster format, at approximately 90-meter resolution. We also demonstrate a simulation framework for capturing uncertainty and presenting estimates as prediction intervals for any region of interest of any size and composition within the study region. Used in concert with previously published demographic estimates, our population estimates allowed for predictions of the population under 5 in ten administrative wards that fit strongly with reference data collected during polio vaccination campaigns.},
keywords = {Demographics, Nigeria, Polio, Population, Settlement mapping},
pubstate = {published},
tppubtype = {article}
}
Wesolowski, Amy; Erbach-Schoenberg, Elisabeth; Tatem, Andrew J.; Lourenço, Christopher; Viboud, Cecile; Charu, Vivek; Eagle, Nathan; Engø-Monsen, Kenth; Qureshi, Taimur; Buckee, Caroline O.; Metcalf, C. J. E.
Multinational patterns of seasonal asymmetry in human movement influence infectious disease dynamics Journal Article
In: Nature Communications, vol. 8, no. 1, pp. 2069, 2017, ISSN: 2041-1723.
Abstract | Links | BibTeX | Tags:
@article{Wesolowski2017,
title = {Multinational patterns of seasonal asymmetry in human movement influence infectious disease dynamics},
author = {Amy Wesolowski and Elisabeth Erbach-Schoenberg and Andrew J. Tatem and Christopher Lourenço and Cecile Viboud and Vivek Charu and Nathan Eagle and Kenth Engø-Monsen and Taimur Qureshi and Caroline O. Buckee and C. J. E. Metcalf},
url = {https://doi.org/10.1038/s41467-017-02064-4},
doi = {10.1038/s41467-017-02064-4},
issn = {2041-1723},
year = {2017},
date = {2017-12-12},
journal = {Nature Communications},
volume = {8},
number = {1},
pages = {2069},
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.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Tejedor‐Garavito, Natalia; Dlamini, Nomcebo; Pindolia, Deepa; Soble, Adam; Ruktanonchai, Nick W.; Alegana, Victor; Menach, Arnaud Le; Ntshalintshali, Nyasatu; Dlamini, Bongani; Smith, David L.; Tatem, Andrew J.; Kunene, Simon
Travel patterns and demographic characteristics of malaria cases in Swaziland, 2010--2014 Journal Article
In: Malaria Journal, vol. 16, no. 1, pp. 359, 2017, ISSN: 1475-2875.
Abstract | Links | BibTeX | Tags:
@article{Tejedor‐Garavito2017,
title = {Travel patterns and demographic characteristics of malaria cases in Swaziland, 2010--2014},
author = {Natalia Tejedor‐Garavito and Nomcebo Dlamini and Deepa Pindolia and Adam Soble and Nick W. Ruktanonchai and Victor Alegana and Arnaud Le Menach and Nyasatu Ntshalintshali and Bongani Dlamini and David L. Smith and Andrew J. Tatem and Simon Kunene},
url = {https://doi.org/10.1186/s12936-017-2004-8},
doi = {10.1186/s12936-017-2004-8},
issn = {1475-2875},
year = {2017},
date = {2017-09-08},
journal = {Malaria Journal},
volume = {16},
number = {1},
pages = {359},
abstract = {As Swaziland progresses towards national malaria elimination, the importation of parasites into receptive areas becomes increasingly important. Imported infections have the potential to instigate local transmission and sustain local parasite reservoirs.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Pezzulo, Carla; Hornby, Graeme M.; Sorichetta, Alessandro; Gaughan, Andrea E.; Linard, Catherine; Bird, Tomas J.; Kerr, David; Lloyd, Christopher T.; Tatem, Andrew J.
Sub-national mapping of population pyramids and dependency ratios in Africa and Asia Journal Article
In: Scientific Data, vol. 4, no. 1, pp. 170089, 2017, ISSN: 2052-4463.
Abstract | Links | BibTeX | Tags:
@article{Pezzulo2017,
title = {Sub-national mapping of population pyramids and dependency ratios in Africa and Asia},
author = {Carla Pezzulo and Graeme M. Hornby and Alessandro Sorichetta and Andrea E. Gaughan and Catherine Linard and Tomas J. Bird and David Kerr and Christopher T. Lloyd and Andrew J. Tatem},
url = {https://doi.org/10.1038/sdata.2017.89},
doi = {10.1038/sdata.2017.89},
issn = {2052-4463},
year = {2017},
date = {2017-07-19},
journal = {Scientific Data},
volume = {4},
number = {1},
pages = {170089},
abstract = {The age group composition of populations varies substantially across continents and within countries, and is linked to levels of development, health status and poverty. The subnational variability in the shape of the population pyramid as well as the respective dependency ratio are reflective of the different levels of development of a country and are drivers for a country's economic prospects and health burdens. Whether measured as the ratio between those of working age and those young and old who are dependent upon them, or through separate young and old-age metrics, dependency ratios are often highly heterogeneous between and within countries. Assessments of subnational dependency ratio and age structure patterns have been undertaken for specific countries and across high income regions, but to a lesser extent across the low income regions. In the framework of the WorldPop Project, through the assembly of over 100 million records across 6,389 subnational administrative units, subnational dependency ratio and high resolution gridded age/sex group datasets were produced for 87 countries in Africa and Asia.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Thomson, Dana R.; Stevens, Forrest R.; Ruktanonchai, Nick W.; Tatem, Andrew J.; Castro, Marcia C.
GridSample: an R package to generate household survey primary sampling units (PSUs) from gridded population data Journal Article
In: International Journal of Health Geographics, vol. 16, no. 1, pp. 25, 2017, ISSN: 1476-072X.
Abstract | Links | BibTeX | Tags:
@article{Thomson2017,
title = {GridSample: an R package to generate household survey primary sampling units (PSUs) from gridded population data},
author = {Dana R. Thomson and Forrest R. Stevens and Nick W. Ruktanonchai and Andrew J. Tatem and Marcia C. Castro},
url = {https://doi.org/10.1186/s12942-017-0098-4},
doi = {10.1186/s12942-017-0098-4},
issn = {1476-072X},
year = {2017},
date = {2017-07-19},
journal = {International Journal of Health Geographics},
volume = {16},
number = {1},
pages = {25},
abstract = {Household survey data are collected by governments, international organizations, and companies to prioritize policies and allocate billions of dollars. Surveys are typically selected from recent census data; however, census data are often outdated or inaccurate. This paper describes how gridded population data might instead be used as a sample frame, and introduces the R GridSample algorithm for selecting primary sampling units (PSU) for complex household surveys with gridded population data. With a gridded population dataset and geographic boundary of the study area, GridSample allows a two-step process to sample ``seed'' cells with probability proportionate to estimated population size, then ``grows'' PSUs until a minimum population is achieved in each PSU. The algorithm permits stratification and oversampling of urban or rural areas. The approximately uniform size and shape of grid cells allows for spatial oversampling, not possible in typical surveys, possibly improving small area estimates with survey results.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Takahashi, Saki; Metcalf, C. Jessica E.; Ferrari, Matthew J.; Tatem, Andrew J.; Lessler, Justin
The geography of measles vaccination in the African Great Lakes region Journal Article
In: Nature Communications, vol. 8, no. 1, pp. 15585, 2017, ISSN: 2041-1723.
Abstract | Links | BibTeX | Tags:
@article{Takahashi2017,
title = {The geography of measles vaccination in the African Great Lakes region},
author = {Saki Takahashi and C. Jessica E. Metcalf and Matthew J. Ferrari and Andrew J. Tatem and Justin Lessler},
url = {https://doi.org/10.1038/ncomms15585},
doi = {10.1038/ncomms15585},
issn = {2041-1723},
year = {2017},
date = {2017-05-25},
journal = {Nature Communications},
volume = {8},
number = {1},
pages = {15585},
abstract = {Expanded access to measles vaccination was among the most successful public health interventions of recent decades. All WHO regions currently target measles elimination by 2020, yet continued measles circulation makes that goal seem elusive. Using Demographic and Health Surveys with generalized additive models, we quantify spatial patterns of measles vaccination in ten contiguous countries in the African Great Lakes region between 2009--2014. Seven countries have `coldspots' where vaccine coverage is below the WHO target of 80%. Over 14 million children under 5 years of age live in coldspots across the region, and a total of 8--12 million children are unvaccinated. Spatial patterns of vaccination do not map directly onto sub-national administrative units and transnational coldspots exist. Clustering of low vaccination areas may allow for pockets of susceptibility that sustain circulation despite high overall coverage. Targeting at-risk areas and transnational coordination are likely required to eliminate measles in the region.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Takahashi, Saki; Metcalf, C. Jessica E.; Ferrari, Matthew J.; Tatem, Andrew J.; Lessler, Justin
The geography of measles vaccination in the African Great Lakes region Journal Article
In: Nature Communications, vol. 8, no. 1, pp. 15585, 2017, ISSN: 2041-1723.
Abstract | Links | BibTeX | Tags:
@article{Takahashi2017b,
title = {The geography of measles vaccination in the African Great Lakes region},
author = {Saki Takahashi and C. Jessica E. Metcalf and Matthew J. Ferrari and Andrew J. Tatem and Justin Lessler},
url = {https://doi.org/10.1038/ncomms15585},
doi = {10.1038/ncomms15585},
issn = {2041-1723},
year = {2017},
date = {2017-05-25},
journal = {Nature Communications},
volume = {8},
number = {1},
pages = {15585},
abstract = {Expanded access to measles vaccination was among the most successful public health interventions of recent decades. All WHO regions currently target measles elimination by 2020, yet continued measles circulation makes that goal seem elusive. Using Demographic and Health Surveys with generalized additive models, we quantify spatial patterns of measles vaccination in ten contiguous countries in the African Great Lakes region between 2009--2014. Seven countries have `coldspots' where vaccine coverage is below the WHO target of 80%. Over 14 million children under 5 years of age live in coldspots across the region, and a total of 8--12 million children are unvaccinated. Spatial patterns of vaccination do not map directly onto sub-national administrative units and transnational coldspots exist. Clustering of low vaccination areas may allow for pockets of susceptibility that sustain circulation despite high overall coverage. Targeting at-risk areas and transnational coordination are likely required to eliminate measles in the region.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Alegana, Victor A.; Wright, Jim; Pezzulo, Carla; Tatem, Andrew J.; Atkinson, Peter M.
Treatment-seeking behaviour in low- and middle-income countries estimated using a Bayesian model Journal Article
In: BMC Medical Research Methodology, vol. 17, no. 1, pp. 67, 2017, ISSN: 1471-2288.
Abstract | Links | BibTeX | Tags:
@article{Alegana2017,
title = {Treatment-seeking behaviour in low- and middle-income countries estimated using a Bayesian model},
author = {Victor A. Alegana and Jim Wright and Carla Pezzulo and Andrew J. Tatem and Peter M. Atkinson},
url = {https://doi.org/10.1186/s12874-017-0346-0},
doi = {10.1186/s12874-017-0346-0},
issn = {1471-2288},
year = {2017},
date = {2017-04-20},
journal = {BMC Medical Research Methodology},
volume = {17},
number = {1},
pages = {67},
abstract = {Seeking treatment in formal healthcare for uncomplicated infections is vital to combating disease in low- and middle-income countries (LMICs). Healthcare treatment-seeking behaviour varies within and between communities and is modified by socio-economic, demographic, and physical factors. As a result, it remains a challenge to quantify healthcare treatment-seeking behaviour using a metric that is comparable across communities. Here, we present an application for transforming individual categorical responses (actions related to fever) to a continuous probabilistic estimate of fever treatment for one country in Sub-Saharan Africa (SSA).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Dudas, Gytis; Carvalho, Luiz Max; Bedford, Trevor; Tatem, Andrew J.; Baele, Guy; Faria, Nuno R.; Park, Daniel J.; Ladner, Jason T.; Arias, Armando; Asogun, Danny; Bielejec, Filip; Caddy, Sarah L.; Cotten, Matthew; DÁmbrozio, Jonathan; Dellicour, Simon; Caro, Antonino Di; Diclaro, Joseph W.; Duraffour, Sophie; Elmore, Michael J.; Fakoli, Lawrence S.; Faye, Ousmane; Gilbert, Merle L.; Gevao, Sahr M.; Gire, Stephen; Gladden-Young, Adrianne; Gnirke, Andreas; Goba, Augustine; Grant, Donald S.; Haagmans, Bart L.; Hiscox, Julian A.; Jah, Umaru; Kugelman, Jeffrey R.; Liu, Di; Lu, Jia; Malboeuf, Christine M.; Mate, Suzanne; Matthews, David A.; Matranga, Christian B.; Meredith, Luke W.; Qu, James; Quick, Joshua; Pas, Suzan D.; Phan, My V. T.; Pollakis, Georgios; Reusken, Chantal B.; Sanchez-Lockhart, Mariano; Schaffner, Stephen F.; Schieffelin, John S.; Sealfon, Rachel S.; Simon-Loriere, Etienne; Smits, Saskia L.; Stoecker, Kilian; Thorne, Lucy; Tobin, Ekaete Alice; Vandi, Mohamed A.; Watson, Simon J.; West, Kendra; Whitmer, Shannon; Wiley, Michael R.; Winnicki, Sarah M.; Wohl, Shirlee; Wölfel, Roman; Yozwiak, Nathan L.; Andersen, Kristian G.; Blyden, Sylvia O.; Bolay, Fatorma; Carroll, Miles W.; Dahn, Bernice; Diallo, Boubacar; Formenty, Pierre; Fraser, Christophe; Gao, George F.; Garry, Robert F.; Goodfellow, Ian; Günther, Stephan; Happi, Christian T.; Holmes, Edward C.; Kargbo, Brima; Ke"ita, Sakoba; Kellam, Paul; Koopmans, Marion P. G.; Kuhn, Jens H.; Loman, Nicholas J.; Magassouba, N'Faly; Naidoo, Dhamari; Nichol, Stuart T.; Nyenswah, Tolbert; Palacios, Gustavo; Pybus, Oliver G.; Sabeti, Pardis C.; Sall, Amadou; Ströher, Ute; Wurie, Isatta; Suchard, Marc A.; Lemey, Philippe; Rambaut, Andrew
Virus genomes reveal factors that spread and sustained the Ebola epidemic Journal Article
In: Nature, vol. 544, no. 7650, pp. 309-315, 2017, ISSN: 1476-4687.
Abstract | Links | BibTeX | Tags:
@article{Dudas2017,
title = {Virus genomes reveal factors that spread and sustained the Ebola epidemic},
author = {Gytis Dudas and Luiz Max Carvalho and Trevor Bedford and Andrew J. Tatem and Guy Baele and Nuno R. Faria and Daniel J. Park and Jason T. Ladner and Armando Arias and Danny Asogun and Filip Bielejec and Sarah L. Caddy and Matthew Cotten and Jonathan DÁmbrozio and Simon Dellicour and Antonino Di Caro and Joseph W. Diclaro and Sophie Duraffour and Michael J. Elmore and Lawrence S. Fakoli and Ousmane Faye and Merle L. Gilbert and Sahr M. Gevao and Stephen Gire and Adrianne Gladden-Young and Andreas Gnirke and Augustine Goba and Donald S. Grant and Bart L. Haagmans and Julian A. Hiscox and Umaru Jah and Jeffrey R. Kugelman and Di Liu and Jia Lu and Christine M. Malboeuf and Suzanne Mate and David A. Matthews and Christian B. Matranga and Luke W. Meredith and James Qu and Joshua Quick and Suzan D. Pas and My V. T. Phan and Georgios Pollakis and Chantal B. Reusken and Mariano Sanchez-Lockhart and Stephen F. Schaffner and John S. Schieffelin and Rachel S. Sealfon and Etienne Simon-Loriere and Saskia L. Smits and Kilian Stoecker and Lucy Thorne and Ekaete Alice Tobin and Mohamed A. Vandi and Simon J. Watson and Kendra West and Shannon Whitmer and Michael R. Wiley and Sarah M. Winnicki and Shirlee Wohl and Roman Wölfel and Nathan L. Yozwiak and Kristian G. Andersen and Sylvia O. Blyden and Fatorma Bolay and Miles W. Carroll and Bernice Dahn and Boubacar Diallo and Pierre Formenty and Christophe Fraser and George F. Gao and Robert F. Garry and Ian Goodfellow and Stephan Günther and Christian T. Happi and Edward C. Holmes and Brima Kargbo and Sakoba Ke"ita and Paul Kellam and Marion P. G. Koopmans and Jens H. Kuhn and Nicholas J. Loman and N'Faly Magassouba and Dhamari Naidoo and Stuart T. Nichol and Tolbert Nyenswah and Gustavo Palacios and Oliver G. Pybus and Pardis C. Sabeti and Amadou Sall and Ute Ströher and Isatta Wurie and Marc A. Suchard and Philippe Lemey and Andrew Rambaut},
url = {https://doi.org/10.1038/nature22040},
doi = {10.1038/nature22040},
issn = {1476-4687},
year = {2017},
date = {2017-04-01},
journal = {Nature},
volume = {544},
number = {7650},
pages = {309-315},
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.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Tatem, Andrew J.
WorldPop, open data for spatial demography Journal Article
In: Scientific Data, vol. 4, no. 1, pp. 170004, 2017, ISSN: 2052-4463.
Abstract | Links | BibTeX | Tags:
@article{Tatem2017,
title = {WorldPop, open data for spatial demography},
author = {Andrew J. Tatem},
url = {https://doi.org/10.1038/sdata.2017.4},
doi = {10.1038/sdata.2017.4},
issn = {2052-4463},
year = {2017},
date = {2017-01-31},
journal = {Scientific Data},
volume = {4},
number = {1},
pages = {170004},
abstract = {High resolution, contemporary data on human population distributions, their characteristics and changes over time are a prerequisite for the accurate measurement of the impacts of population growth, for monitoring changes and for planning interventions. WorldPop aims to meet these needs through the provision of detailed and open access spatial demographic datasets built using transparent approaches. The Scientific Data WorldPop collection brings together descriptor papers on these datasets and is introduced here.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Lloyd, Christopher T.; Sorichetta, Alessandro; Tatem, Andrew J.
High resolution global gridded data for use in population studies Journal Article
In: Scientific Data, vol. 4, no. 1, pp. 170001, 2017, ISSN: 2052-4463.
Abstract | Links | BibTeX | Tags:
@article{Lloyd2017,
title = {High resolution global gridded data for use in population studies},
author = {Christopher T. Lloyd and Alessandro Sorichetta and Andrew J. Tatem},
url = {https://doi.org/10.1038/sdata.2017.1},
doi = {10.1038/sdata.2017.1},
issn = {2052-4463},
year = {2017},
date = {2017-01-31},
journal = {Scientific Data},
volume = {4},
number = {1},
pages = {170001},
abstract = {Recent years have seen substantial growth in openly available satellite and other geospatial data layers, which represent a range of metrics relevant to global human population mapping at fine spatial scales. The specifications of such data differ widely and therefore the harmonisation of data layers is a prerequisite to constructing detailed and contemporary spatial datasets which accurately describe population distributions. Such datasets are vital to measure impacts of population growth, monitor change, and plan interventions. To this end the WorldPop Project has produced an open access archive of 3 and 30 arc-second resolution gridded data. Four tiled raster datasets form the basis of the archive: (i) Viewfinder Panoramas topography clipped to Global ADMinistrative area (GADM) coastlines; (ii) a matching ISO 3166 country identification grid; (iii) country area; (iv) and slope layer. Further layers include transport networks, landcover, nightlights, precipitation, travel time to major cities, and waterways. Datasets and production methodology are here described. The archive can be downloaded both from the WorldPop Dataverse Repository and the WorldPop Project website.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Linard, Catherine; Kabaria, Caroline W.; Gilbert, Marius; Tatem, Andrew J.; Gaughan, Andrea E.; Stevens, Forrest R.; Sorichetta, Alessandro; Noor, Abdisalan M.; Snow, Robert W.
Modelling changing population distributions: an example of the Kenyan Coast, 1979–2009 Journal Article
In: International Journal of Digital Earth, vol. 10, no. 10, pp. 1017-1029, 2017, (PMID: 29098016).
@article{doi:10.1080/17538947.2016.1275829,
title = {Modelling changing population distributions: an example of the Kenyan Coast, 1979–2009},
author = {Catherine Linard and Caroline W. Kabaria and Marius Gilbert and Andrew J. Tatem and Andrea E. Gaughan and Forrest R. Stevens and Alessandro Sorichetta and Abdisalan M. Noor and Robert W. Snow},
url = {https://doi.org/10.1080/17538947.2016.1275829},
doi = {10.1080/17538947.2016.1275829},
year = {2017},
date = {2017-01-01},
journal = {International Journal of Digital Earth},
volume = {10},
number = {10},
pages = {1017-1029},
publisher = {Taylor & Francis},
note = {PMID: 29098016},
keywords = {},
pubstate = {published},
tppubtype = {article}
}