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Shen J. Modelling the roles of visitor flows and returning migrants in the spatial diffusion of COVID-19 from Wuhan city in China. APPLIED GEOGRAPHY (SEVENOAKS, ENGLAND) 2023; 155:102971. [PMID: 37123661 PMCID: PMC10121107 DOI: 10.1016/j.apgeog.2023.102971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 04/03/2023] [Accepted: 04/15/2023] [Indexed: 05/03/2023]
Abstract
COVID-19 has spread to many cities and countries in the world since the major outbreak in Wuhan city in later 2019. Population flow is the main channel of COVID-19 transmission between different cities and countries. This study recognizes that the flows of different population groups such as visitors and migrants returning to hometown are different in nature due to different length of stay and exposure to infection risks, contributing to the spatial diffusion of COVID-19 differently. To model population flows and the spatial diffusion of COVID-19 more accurately, a population group based SEIR (susceptible-exposed-infectious-recovered) metapopulation model is developed consisting of 32 regions including Wuhan, the rest of Hubei and other 30 provinces in Mainland China. The paper found that, in terms of the total export, Wuhan residents as visitors and Wuhan migrants returned to hometown were the first and second largest contributors in the simulation period. In terms of the net export, Wuhan migrants returned to hometown were the largest contributor, followed by Wuhan residents as visitors.
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Affiliation(s)
- Jianfa Shen
- Department of Geography and Resource Management, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region of China
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Cissoko M, Landier J, Kouriba B, Sangare AK, Katilé A, Djimde AA, Berthé I, Traore S, Thera I, Hadiata M, Sogodogo E, Coulibaly K, Guindo A, Dembele O, Sanogo S, Doumbia Z, Dara C, Altmann M, Bonnet E, Balique H, Sagaon-Teyssier L, Vidal L, Sagara I, Bendiane MK, Gaudart J. SARS-CoV-2 seroprevalence and living conditions in Bamako (Mali): a cross-sectional multistage household survey after the first epidemic wave, 2020. BMJ Open 2023; 13:e067124. [PMID: 37080622 PMCID: PMC10123860 DOI: 10.1136/bmjopen-2022-067124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/22/2023] Open
Abstract
OBJECTIVES In low-income settings with limited access to diagnosis, COVID-19 information is scarce. In September 2020, after the first COVID-19 wave, Mali reported 3086 confirmed cases and 130 deaths. Most reports originated from Bamako, with 1532 cases and 81 deaths (2.42 million inhabitants). This observed prevalence of 0.06% appeared very low. Our objective was to estimate SARS-CoV-2 infection among inhabitants of Bamako, after the first epidemic wave. We assessed demographic, social and living conditions, health behaviours and knowledges associated with SARS-CoV-2 seropositivity. SETTINGS We conducted a cross-sectional multistage household survey during September 2020, in three neighbourhoods of the commune VI (Bamako), where 30% of the cases were reported. PARTICIPANTS We recruited 1526 inhabitants in 3 areas, that is, 306 households, and 1327 serological results (≥1 years), 220 household questionnaires and collected answers for 962 participants (≥12 years). PRIMARY AND SECONDARY OUTCOME MEASURES We measured serological status, detecting SARS-CoV-2 spike protein antibodies in blood sampled. We documented housing conditions and individual health behaviours through questionnaires among participants. We estimated the number of SARS-CoV-2 infections and deaths in the population of Bamako using the age and sex distributions. RESULTS The prevalence of SARS-CoV-2 seropositivity was 16.4% (95% CI 15.1% to 19.1%) after adjusting on the population structure. This suggested that ~400 000 cases and ~2000 deaths could have occurred of which only 0.4% of cases and 5% of deaths were officially reported. Questionnaires analyses suggested strong agreement with washing hands but lower acceptability of movement restrictions (lockdown/curfew), and mask wearing. CONCLUSIONS The first wave of SARS-CoV-2 spread broadly in Bamako. Expected fatalities remained limited largely due to the population age structure and the low prevalence of comorbidities. Improving diagnostic capacities to encourage testing and preventive behaviours, and avoiding the spread of false information remain key pillars, regardless of the developed or developing setting. ETHICS This study was registered in the registry of the ethics committee of the Faculty of Medicine and Odonto-Stomatology and the Faculty of Pharmacy, Bamako, Mali, under the number: 2020/162/CA/FMOS/FAPH.
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Affiliation(s)
- Mady Cissoko
- SESSTIM UMR1252, Aix Marseille Univ, IRD, INSERM, ISSPAM, Marseille, France
- Malaria Research and Training Centre Ogobara Doumbo (MRTC-OD), Université des Sciences, des Techniques et des Technologies de Bamako, FMOS-FAPH, Mali-NIAID-ICER, Bamako, Mali
| | - Jordi Landier
- SESSTIM UMR1252, Aix Marseille Univ, IRD, INSERM, ISSPAM, Marseille, France
| | - Bourema Kouriba
- Centre d'Infectiologie Clinique Charles Mérieux, Bamako, Mali
| | | | - Abdoulaye Katilé
- SESSTIM UMR1252, Aix Marseille Univ, IRD, INSERM, ISSPAM, Marseille, France
- Malaria Research and Training Centre Ogobara Doumbo (MRTC-OD), Université des Sciences, des Techniques et des Technologies de Bamako, FMOS-FAPH, Mali-NIAID-ICER, Bamako, Mali
| | - Abdoulaye A Djimde
- Malaria Research and Training Centre Ogobara Doumbo (MRTC-OD), Université des Sciences, des Techniques et des Technologies de Bamako, FMOS-FAPH, Mali-NIAID-ICER, Bamako, Mali
| | - Ibrahima Berthé
- Malaria Research and Training Centre Ogobara Doumbo (MRTC-OD), Université des Sciences, des Techniques et des Technologies de Bamako, FMOS-FAPH, Mali-NIAID-ICER, Bamako, Mali
- Direction générale de la santé et de l'hygiène publique du ministère de la santé et du développement social, Bamako, Mali
| | - Siriman Traore
- Malaria Research and Training Centre Ogobara Doumbo (MRTC-OD), Université des Sciences, des Techniques et des Technologies de Bamako, FMOS-FAPH, Mali-NIAID-ICER, Bamako, Mali
| | - Ismaila Thera
- Malaria Research and Training Centre Ogobara Doumbo (MRTC-OD), Université des Sciences, des Techniques et des Technologies de Bamako, FMOS-FAPH, Mali-NIAID-ICER, Bamako, Mali
| | - Maiga Hadiata
- Centre d'Infectiologie Clinique Charles Mérieux, Bamako, Mali
| | | | - Karyn Coulibaly
- Centre d'Infectiologie Clinique Charles Mérieux, Bamako, Mali
| | - Abdoulaye Guindo
- Direction générale de la santé et de l'hygiène publique du ministère de la santé et du développement social, Bamako, Mali
| | - Ousmane Dembele
- Direction générale de la santé et de l'hygiène publique du ministère de la santé et du développement social, Bamako, Mali
| | - Souleymane Sanogo
- Direction régionale de Tombouctou et établissement public hospitalier de Tombouctou, Tombouctou, Mali
| | - Zoumana Doumbia
- Direction régionale de Tombouctou et établissement public hospitalier de Tombouctou, Tombouctou, Mali
| | - Charles Dara
- Direction régionale de Tombouctou et établissement public hospitalier de Tombouctou, Tombouctou, Mali
| | | | | | - Hubert Balique
- Direction générale de la santé et de l'hygiène publique du ministère de la santé et du développement social, Bamako, Mali
| | - Luis Sagaon-Teyssier
- SESSTIM UMR1252, Aix Marseille Univ, IRD, INSERM, ISSPAM, Marseille, France
- ARCAD Santé Plus/Centre Intégré de Recherche, de Soins et d'Action Communautaire (CIRSAC), Bamako, Mali
| | - Laurent Vidal
- SESSTIM UMR1252, Aix Marseille Univ, IRD, INSERM, ISSPAM, Marseille, France
| | - Issaka Sagara
- Malaria Research and Training Centre Ogobara Doumbo (MRTC-OD), Université des Sciences, des Techniques et des Technologies de Bamako, FMOS-FAPH, Mali-NIAID-ICER, Bamako, Mali
| | | | - Jean Gaudart
- SESSTIM UMR1252, Aix Marseille Univ, IRD, INSERM, ISSPAM, Marseille, France
- Biostatictics & ICT, AP-HM, Marseille, France
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Turnbull S, Hobbs M, Gray L, Harvey E, Scarrold W, O'Neale D. Investigating the transmission risk of infectious disease outbreaks through the Aotearoa Co-incidence Network (ACN): a population-based study. THE LANCET REGIONAL HEALTH. WESTERN PACIFIC 2022; 20:100351. [PMID: 35024675 PMCID: PMC8733170 DOI: 10.1016/j.lanwpc.2021.100351] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The emergence and re-emergence of infectious diseases presents a significant challenge to public health and broader society. This study utilises novel nationwide data to calculate the transmission risk and potential inequity of infectious disease outbreaks through use of network analysis. METHODS Nationwide employment and education microdata (∼4.7 million individuals in Aotearoa New Zealand) were used to develop the Aotearoa Co-incidence Network (ACN). The ACN considers connections generated when individuals are employed at the same workplaces or enrolled at the same schools. Through forms of network analysis, connections between geospatial areas can be established and provide proxy measures of infectious disease transmission risk. The ACN was also overlayed with nationwide population vulnerability data based on the number of older adults (>65 years) and individuals with long-term health conditions. FINDINGS We identify areas that have both high potential transmission risk (i.e., highly connected) and high vulnerability to infectious diseases. Community detection identified geographic boundaries that can be relevant to the application of regional restrictions for limiting infectious disease transmission. INTERPRETATION Integrating novel network science and geospatial analytics provides a simple way to study infectious disease transmission risk and population vulnerability to outbreaks. Our replicable method has utility for researchers globally with access to such data. It can help inform equitable preparation for, and responses to infectious disease outbreaks. FUNDING This project was funded by the Health Research Council of New Zealand (20/1442) and from the NZ Government via Ministry for Business Innovation and Employment and Department of Prime Minister and Cabinet.
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Affiliation(s)
- S.M. Turnbull
- Department of Physics, University of Auckland, Auckland, New Zealand
- Te Pūnaha Matatini, University of Auckland, Auckland, New Zealand
| | - M. Hobbs
- GeoHealth Laboratory, University of Canterbury, Christchurch, Canterbury, New Zealand
- School of Health Sciences, University of Canterbury, Christchurch, Canterbury, New Zealand
| | - L. Gray
- Department of Primary Health Care and General Practice, University of Otago, Wellington, New Zealand
| | - E.P. Harvey
- Te Pūnaha Matatini, University of Auckland, Auckland, New Zealand
- M.E. Research, Takapuna, Auckland, New Zealand
| | - W.M.L. Scarrold
- Te Pūnaha Matatini, University of Auckland, Auckland, New Zealand
- Mathematical Institute, University of Oxford, Oxford, United Kingdom
- Institute for New Economic Thinking, Oxford Martin School, Oxford, United Kingdom
| | - D.R.J. O'Neale
- Department of Physics, University of Auckland, Auckland, New Zealand
- Te Pūnaha Matatini, University of Auckland, Auckland, New Zealand
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