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Hagedorn B, Zhou NA, Fagnant-Sperati CS, Shirai JH, Gauld J, Wang Y, Boyle DS, Meschke JS. Estimates of the cost to build a stand-alone environmental surveillance system for typhoid in low- and middle-income countries. PLOS Glob Public Health 2023; 3:e0001074. [PMID: 36962955 PMCID: PMC10021573 DOI: 10.1371/journal.pgph.0001074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 12/02/2022] [Indexed: 01/27/2023]
Abstract
The typhoid conjugate vaccine is a safe and effective method for preventing Salmonella enterica serovar Typhi (typhoid) and the WHO's guidance supports its use in locations with ongoing transmission. However, many countries lack a robust clinical surveillance system, making it challenging to determine where to use the vaccine. Environmental surveillance is one alternative approach to identify ongoing transmission, but the cost to implement such a strategy is previously unknown. This paper estimated the cost of setting up and operating an environmental surveillance program for thirteen protocols that are in development, including thirteen cost components and twenty-seven pieces of equipment. Unit costs were obtained from research labs involved in protocol development and equipment information was obtained from manufacturers and the expert opinion of individuals in participating labs. We used Monte Carlo simulations to estimate the costs and the input parameters were modeled as distributions to incorporate the uncertainty. Total costs per sample including setup, overhead, and operational costs, range from $357-794 at a scale of 25 sites to $116-532 at 125 sites. Operational costs (ongoing expenditures) range from $218-584 per sample at a scale of 25 sites to $74-421 at 125 sites. Eleven of the thirteen protocols have operational costs below $200, at this higher scale. Protocols with higher up-front equipment costs benefit more from scale efficiencies and sensitivity analyses show that laboratory labor, processes, and consumables are the primary drivers of uncertainty. At scale, environmental surveillance for typhoid may be affordable (depending on the protocol, scale, and geographic context), though cost will need to be considered alongside future evaluations of test sensitivity. Opportunities to leverage existing infrastructure and multi-disease platforms may be necessary to further reduce costs.
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Affiliation(s)
- Brittany Hagedorn
- Institute for Disease Modeling, Bill & Melinda Gates Foundation, Seattle, WA, United States of America
| | - Nicolette A Zhou
- Environmental and Occupational Health, University of Washington, Seattle, WA, United States of America
| | | | - Jeffry H Shirai
- Environmental and Occupational Health, University of Washington, Seattle, WA, United States of America
| | - Jillian Gauld
- Institute for Disease Modeling, Bill & Melinda Gates Foundation, Seattle, WA, United States of America
| | - Yuke Wang
- Center of Global Safe Water, Sanitation, and Hygiene in the Hubert Department of Global Health, Emory University, Atlanta, GA, United States of America
| | - David S Boyle
- Diagnostics Program, PATH, Seattle, WA, United States of America
| | - John Scott Meschke
- Environmental and Occupational Health, University of Washington, Seattle, WA, United States of America
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2
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Wigley A, Lorin J, Hogan D, Utazi CE, Hagedorn B, Dansereau E, Tatem AJ, Tejedor-Garavito N. Estimates of the number and distribution of zero-dose and under-immunised children across remote-rural, urban, and conflict-affected settings in low and middle-income countries. PLOS Glob Public Health 2022; 2:e0001126. [PMID: 36962682 PMCID: PMC10021885 DOI: 10.1371/journal.pgph.0001126] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 10/05/2022] [Indexed: 02/11/2023]
Abstract
While there has been great success in increasing the coverage of new childhood vaccines globally, expanding routine immunization to reliably reach all children and communities has proven more challenging in many low- and middle-income countries. Achieving this requires vaccination strategies and interventions that identify and target those unvaccinated, guided by the most current and detailed data regarding their size and spatial distribution. Through the integration and harmonisation of a range of geospatial data sets, including population, vaccination coverage, travel-time, settlement type, and conflict locations. We estimated the numbers of children un- or under-vaccinated for measles and diphtheria-tetanus-pertussis, within remote-rural, urban, and conflict-affected locations. We explored how these numbers vary both nationally and sub-nationally, and assessed what proportions of children these categories captured, for 99 lower- and middle-income countries, for which data was available. We found that substantial heterogeneities exist both between and within countries. Of the total 14,030,486 children unvaccinated for DTP1, over 11% (1,656,757) of un- or under-vaccinated children were in remote-rural areas, more than 28% (2,849,671 and 1,129,915) in urban and peri-urban areas, and up to 60% in other settings, with nearly 40% found to be within 1-hour of the nearest town or city (though outside of urban/peri-urban areas). Of the total number of those unvaccinated, we estimated between 6% and 15% (826,976 to 2,068,785) to be in conflict-affected locations, based on either broad or narrow definitions of conflict. Our estimates provide insights into the inequalities in vaccination coverage, with the distributions of those unvaccinated varying significantly by country, region, and district. We demonstrate the need for further inquiry and characterisation of those unvaccinated, the thresholds used to define these, and for more country-specific and targeted approaches to defining such populations in the strategies and interventions used to reach them.
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Affiliation(s)
- Adelle Wigley
- WorldPop, Geography and Environmental Science, University of Southampton, Highfield Campus, Southampton, United Kingdom
| | - Josh Lorin
- Gavi, The Vaccine Alliance, Geneva, Switzerland
| | - Dan Hogan
- Gavi, The Vaccine Alliance, Geneva, Switzerland
| | - C. Edson Utazi
- WorldPop, Geography and Environmental Science, University of Southampton, Highfield Campus, Southampton, United Kingdom
| | - Brittany Hagedorn
- Institute for Disease Modelling, Bill & Melinda Gates Foundation, Seattle, Washington, WA, United States of America
| | - Emily Dansereau
- Institute for Disease Modelling, Bill & Melinda Gates Foundation, Seattle, Washington, WA, United States of America
| | - Andrew J. Tatem
- WorldPop, Geography and Environmental Science, University of Southampton, Highfield Campus, Southampton, United Kingdom
| | - Natalia Tejedor-Garavito
- WorldPop, Geography and Environmental Science, University of Southampton, Highfield Campus, Southampton, United Kingdom
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3
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Frey K, Hagedorn B, McCarthy KA, Hutubessy R, Wang SA. Modeling anticipated changes in numbers of SARS-CoV-2 infections within communities due to immunization campaigns. Gates Open Res 2022; 6:7. [PMID: 36299735 PMCID: PMC9576906 DOI: 10.12688/gatesopenres.13448.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2022] [Indexed: 11/20/2022] Open
Abstract
Background: As SARS-CoV-2 spread in early 2020, uncertainty about the scope, duration, and impact of the unfolding outbreaks caused numerous countries to interrupt many routine activities, including health services. Because immunization is an essential health service, modeling changes in SARS-CoV-2 infections among communities and health workers due to different vaccination activities was undertaken to understand the risks and to inform approaches to resume services. Methods: Agent-based modeling examined the impact of Supplemental Immunization Activities (SIAs) delivery strategies on SARS-CoV-2 transmission in communities and health workers for six countries capturing various demographic profiles and health system performance: Angola, Ecuador, Lao PDR, Nepal, Pakistan, and Ukraine. Results: Urban, fixed-post SIAs during periods of high SARS-CoV-2 prevalence increased infections within the community by around 28 [range:0-79] per 1000 vaccinations. House-to-house SIAs in mixed urban and rural contexts may import infections into previously naïve communities. Infections are elevated by around 60 [range:0-230] per 1000 vaccinations, but outcomes are sensitive to prevalence in health workers and SIA timing relative to peak. Conclusions: Incremental increases in SARS-CoV-2 infection due to SIAs was small and in proportion to overall prevalence. Younger populations experience lower transmission intensity and fewer excess infections per childhood vaccine delivered. Large rural populations have lower transmission intensity but face a greater risk of introduction of SARS-CoV-2 during an SIA.
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Affiliation(s)
- Kurt Frey
- Institute for Disease Modeling, Bill & Melinda Gates Foundation, Seattle, WA, 98109, USA
| | - Brittany Hagedorn
- Institute for Disease Modeling, Bill & Melinda Gates Foundation, Seattle, WA, 98109, USA
| | - Kevin A. McCarthy
- Institute for Disease Modeling, Bill & Melinda Gates Foundation, Seattle, WA, 98109, USA
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4
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Frey K, Hagedorn B, McCarthy KA, Hutubessy R, Wang SA. Modeling anticipated changes in numbers of SARS-CoV-2 infections within communities due to immunization campaigns. Gates Open Res 2022; 6:7. [DOI: 10.12688/gatesopenres.13448.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2022] [Indexed: 11/20/2022] Open
Abstract
Background: As SARS-CoV-2 spread in early 2020, uncertainty about the scope, duration, and impact of the unfolding outbreaks caused numerous countries to interrupt many routine activities, including health services. Because immunization is an essential health service, modeling changes in SARS-CoV-2 infections among communities and health workers due to different vaccination activities was undertaken to understand the risks and to inform approaches to resume services. Methods: Agent-based modeling examined the impact of Supplemental Immunization Activities (SIAs) delivery strategies on SARS-CoV-2 transmission in communities and health workers for six countries capturing various demographic profiles and health system performance: Angola, Ecuador, Lao PDR, Nepal, Pakistan, and Ukraine. Results: Urban, fixed-post SIAs during periods of high SARS-CoV-2 prevalence increased infections within the community by around 28 [range:0-79] per 1000 vaccinations. House-to-house SIAs in mixed urban and rural contexts may import infections into previously naïve communities. Infections are elevated by around 60 [range:0-230] per 1000 vaccinations, but outcomes are sensitive to prevalence in health workers and SIA timing relative to peak. Conclusions: Younger populations experience lower transmission intensity and fewer excess infections per childhood vaccine delivered. Large rural populations have lower transmission intensity but face a greater risk of introduction of SARS-CoV-2 during an SIA.
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5
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Utazi CE, Pannell O, Aheto JMK, Wigley A, Tejedor-Garavito N, Wunderlich J, Hagedorn B, Hogan D, Tatem AJ. Assessing the characteristics of un- and under-vaccinated children in low- and middle-income countries: A multi-level cross-sectional study. PLOS Glob Public Health 2022; 2:e0000244. [PMID: 36962232 PMCID: PMC10021434 DOI: 10.1371/journal.pgph.0000244] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 02/03/2022] [Indexed: 11/18/2022]
Abstract
Achieving equity in vaccination coverage has been a critical priority within the global health community. Despite increased efforts recently, certain populations still have a high proportion of un- and under-vaccinated children in many low- and middle-income countries (LMICs). These populations are often assumed to reside in remote-rural areas, urban slums and conflict-affected areas. Here, we investigate the effects of these key community-level factors, alongside a wide range of other individual, household and community level factors, on vaccination coverage. Using geospatial datasets, including cross-sectional data from the most recent Demographic and Health Surveys conducted between 2008 and 2018 in nine LMICs, we fitted Bayesian multi-level binary logistic regression models to determine key community-level and other factors significantly associated with non- and under-vaccination. We analyzed the odds of receipt of the first doses of diphtheria-tetanus-pertussis (DTP1) vaccine and measles-containing vaccine (MCV1), and receipt of all three recommended DTP doses (DTP3) independently, in children aged 12-23 months. In bivariate analyses, we found that remoteness increased the odds of non- and under-vaccination in nearly all the study countries. We also found evidence that living in conflict and urban slum areas reduced the odds of vaccination, but not in most cases as expected. However, the odds of vaccination were more likely to be lower in urban slums than formal urban areas. Our multivariate analyses revealed that the key community variables-remoteness, conflict and urban slum-were sometimes associated with non- and under-vaccination, but they were not frequently predictors of these outcomes after controlling for other factors. Individual and household factors such as maternal utilization of health services, maternal education and ethnicity, were more common predictors of vaccination. Reaching the Immunisation Agenda 2030 target of reducing the number of zero-dose children by 50% by 2030 will require country tailored analyses and strategies to identify and reach missed communities with reliable immunisation services.
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Affiliation(s)
- C Edson Utazi
- WorldPop, School of Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Oliver Pannell
- Flowminder Foundation and WorldPop, School of Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Justice M K Aheto
- WorldPop, School of Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Adelle Wigley
- WorldPop, School of Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Natalia Tejedor-Garavito
- WorldPop, School of Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | | | - Brittany Hagedorn
- Institute for Disease Modeling, Bill & Melinda Gates Foundation, Seattle, Washington, WA, United States of America
| | - Dan Hogan
- Gavi, The Vaccine Alliance, Geneva, Switzerland
| | - Andrew J Tatem
- WorldPop, School of Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
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6
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Procter SR, Abbas K, Flasche S, Griffiths U, Hagedorn B, O'Reilly KM, Jit M. SARS-CoV-2 infection risk during delivery of childhood vaccination campaigns: a modelling study. BMC Med 2021; 19:198. [PMID: 34384441 PMCID: PMC8359640 DOI: 10.1186/s12916-021-02072-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 07/26/2021] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND The COVID-19 pandemic has disrupted the delivery of immunisation services globally. Many countries have postponed vaccination campaigns out of concern about infection risks to the staff delivering vaccination, the children being vaccinated, and their families. The World Health Organization recommends considering both the benefit of preventive campaigns and the risk of SARS-CoV-2 transmission when making decisions about campaigns during COVID-19 outbreaks, but there has been little quantification of the risks. METHODS We modelled excess SARS-CoV-2 infection risk to vaccinators, vaccinees, and their caregivers resulting from vaccination campaigns delivered during a COVID-19 epidemic. Our model used population age structure and contact patterns from three exemplar countries (Burkina Faso, Ethiopia, and Brazil). It combined an existing compartmental transmission model of an underlying COVID-19 epidemic with a Reed-Frost model of SARS-CoV-2 infection risk to vaccinators and vaccinees. We explored how excess risk depends on key parameters governing SARS-CoV-2 transmissibility, and aspects of campaign delivery such as campaign duration, number of vaccinations, and effectiveness of personal protective equipment (PPE) and symptomatic screening. RESULTS Infection risks differ considerably depending on the circumstances in which vaccination campaigns are conducted. A campaign conducted at the peak of a SARS-CoV-2 epidemic with high prevalence and without special infection mitigation measures could increase absolute infection risk by 32 to 45% for vaccinators and 0.3 to 0.5% for vaccinees and caregivers. However, these risks could be reduced to 3.6 to 5.3% and 0.1 to 0.2% respectively by use of PPE that reduces transmission by 90% (as might be achieved with N95 respirators or high-quality surgical masks) and symptomatic screening. CONCLUSIONS SARS-CoV-2 infection risks to vaccinators, vaccinees, and caregivers during vaccination campaigns can be greatly reduced by adequate PPE, symptomatic screening, and appropriate campaign timing. Our results support the use of adequate risk mitigation measures for vaccination campaigns held during SARS-CoV-2 epidemics, rather than cancelling them entirely.
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Affiliation(s)
- Simon R Procter
- Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, UK.
| | - Kaja Abbas
- Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, UK
| | - Stefan Flasche
- Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, UK
| | | | | | - Kathleen M O'Reilly
- Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, UK
| | - Mark Jit
- Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, UK
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7
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Procter SR, Abbas K, Flasche S, Griffiths U, Hagedorn B, O'Reilly KM, Jit M. SARS-CoV-2 infection risk during delivery of childhood vaccination campaigns: a modelling study. medRxiv 2021:2021.05.14.21257215. [PMID: 34031666 PMCID: PMC8142667 DOI: 10.1101/2021.05.14.21257215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The COVID-19 pandemic has disrupted delivery of immunisation services globally. Many countries have postponed vaccination campaigns out of concern about infection risks to staff delivering vaccination, the children being vaccinated and their families. The World Health Organization recommends considering both the benefit of preventive campaigns and the risk of SARS-CoV-2 transmission when making decisions about campaigns during COVID-19 outbreaks, but there has been little quantification of the risks. METHODS We modelled excess SARS-CoV-2 infection risk to vaccinators, vaccinees and their caregivers resulting from vaccination campaigns delivered during a COVID-19 epidemic. Our model used population age-structure and contact patterns from three exemplar countries (Burkina Faso, Ethiopia, and Brazil). It combined an existing compartmental transmission model of an underlying COVID-19 epidemic with a Reed-Frost model of SARS-CoV-2 infection risk to vaccinators and vaccinees. We explored how excess risk depends on key parameters governing SARS-CoV-2 transmissibility, and aspects of campaign delivery such as campaign duration, number of vaccinations, and effectiveness of personal protective equipment (PPE) and symptomatic screening. RESULTS Infection risks differ considerably depending on the circumstances in which vaccination campaigns are conducted. A campaign conducted at the peak of a SARS-CoV-2 epidemic with high prevalence and without special infection mitigation measures could increase absolute infection risk by 32% to 45% for vaccinators, and 0.3% to 0.5% for vaccinees and caregivers. However, these risks could be reduced to 3.6% to 5.3% and 0.1% to 0.2% respectively by use of PPE that reduces transmission by 90% (as might be achieved with N95 respirators or high-quality surgical masks) and symptomatic screening. CONCLUSIONS SARS-CoV-2 infection risks to vaccinators, vaccinees and caregivers during vaccination campaigns can be greatly reduced by adequate PPE, symptomatic screening, and appropriate campaign timing. Our results support the use of adequate risk mitigation measures for vaccination campaigns held during SARS-CoV-2 epidemics, rather than cancelling them entirely.
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Affiliation(s)
- Simon R Procter
- Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom
| | - Kaja Abbas
- Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom
| | - Stefan Flasche
- Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom
| | | | | | - Kathleen M O'Reilly
- Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom
| | - Mark Jit
- Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom
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8
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Kerr CC, Stuart RM, Mistry D, Abeysuriya RG, Rosenfeld K, Hart GR, Núñez RC, Cohen JA, Selvaraj P, Hagedorn B, George L, Jastrzębski M, Izzo AS, Fowler G, Palmer A, Delport D, Scott N, Kelly SL, Bennette CS, Wagner BG, Chang ST, Oron AP, Wenger EA, Panovska-Griffiths J, Famulare M, Klein DJ. Covasim: An agent-based model of COVID-19 dynamics and interventions. PLoS Comput Biol 2021; 17:e1009149. [PMID: 34310589 DOI: 10.1101/2020.05.10.20097469] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 08/05/2021] [Accepted: 06/05/2021] [Indexed: 05/24/2023] Open
Abstract
The COVID-19 pandemic has created an urgent need for models that can project epidemic trends, explore intervention scenarios, and estimate resource needs. Here we describe the methodology of Covasim (COVID-19 Agent-based Simulator), an open-source model developed to help address these questions. Covasim includes country-specific demographic information on age structure and population size; realistic transmission networks in different social layers, including households, schools, workplaces, long-term care facilities, and communities; age-specific disease outcomes; and intrahost viral dynamics, including viral-load-based transmissibility. Covasim also supports an extensive set of interventions, including non-pharmaceutical interventions, such as physical distancing and protective equipment; pharmaceutical interventions, including vaccination; and testing interventions, such as symptomatic and asymptomatic testing, isolation, contact tracing, and quarantine. These interventions can incorporate the effects of delays, loss-to-follow-up, micro-targeting, and other factors. Implemented in pure Python, Covasim has been designed with equal emphasis on performance, ease of use, and flexibility: realistic and highly customized scenarios can be run on a standard laptop in under a minute. In collaboration with local health agencies and policymakers, Covasim has already been applied to examine epidemic dynamics and inform policy decisions in more than a dozen countries in Africa, Asia-Pacific, Europe, and North America.
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Affiliation(s)
- Cliff C Kerr
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Robyn M Stuart
- Department of Mathematical Sciences, University of Copenhagen, Copenhagen, Denmark
- Burnet Institute, Melbourne, Victoria, Australia
| | - Dina Mistry
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | | | - Katherine Rosenfeld
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Gregory R Hart
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Rafael C Núñez
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Jamie A Cohen
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Prashanth Selvaraj
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Brittany Hagedorn
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Lauren George
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | | | - Amanda S Izzo
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Greer Fowler
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Anna Palmer
- Burnet Institute, Melbourne, Victoria, Australia
| | | | - Nick Scott
- Burnet Institute, Melbourne, Victoria, Australia
| | | | - Caroline S Bennette
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Bradley G Wagner
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Stewart T Chang
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Assaf P Oron
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Edward A Wenger
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Jasmina Panovska-Griffiths
- Big Data Institute, University of Oxford, Oxford, United Kingdom
- Wolfson Centre for Mathematical Biology and The Queen's College, University of Oxford, Oxford, United Kingdom
| | - Michael Famulare
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Daniel J Klein
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
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9
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Kerr CC, Stuart RM, Mistry D, Abeysuriya RG, Rosenfeld K, Hart GR, Núñez RC, Cohen JA, Selvaraj P, Hagedorn B, George L, Jastrzębski M, Izzo AS, Fowler G, Palmer A, Delport D, Scott N, Kelly SL, Bennette CS, Wagner BG, Chang ST, Oron AP, Wenger EA, Panovska-Griffiths J, Famulare M, Klein DJ. Covasim: An agent-based model of COVID-19 dynamics and interventions. PLoS Comput Biol 2021; 17:e1009149. [PMID: 34310589 PMCID: PMC8341708 DOI: 10.1371/journal.pcbi.1009149] [Citation(s) in RCA: 175] [Impact Index Per Article: 58.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 08/05/2021] [Accepted: 06/05/2021] [Indexed: 12/23/2022] Open
Abstract
The COVID-19 pandemic has created an urgent need for models that can project epidemic trends, explore intervention scenarios, and estimate resource needs. Here we describe the methodology of Covasim (COVID-19 Agent-based Simulator), an open-source model developed to help address these questions. Covasim includes country-specific demographic information on age structure and population size; realistic transmission networks in different social layers, including households, schools, workplaces, long-term care facilities, and communities; age-specific disease outcomes; and intrahost viral dynamics, including viral-load-based transmissibility. Covasim also supports an extensive set of interventions, including non-pharmaceutical interventions, such as physical distancing and protective equipment; pharmaceutical interventions, including vaccination; and testing interventions, such as symptomatic and asymptomatic testing, isolation, contact tracing, and quarantine. These interventions can incorporate the effects of delays, loss-to-follow-up, micro-targeting, and other factors. Implemented in pure Python, Covasim has been designed with equal emphasis on performance, ease of use, and flexibility: realistic and highly customized scenarios can be run on a standard laptop in under a minute. In collaboration with local health agencies and policymakers, Covasim has already been applied to examine epidemic dynamics and inform policy decisions in more than a dozen countries in Africa, Asia-Pacific, Europe, and North America.
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Affiliation(s)
- Cliff C. Kerr
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Robyn M. Stuart
- Department of Mathematical Sciences, University of Copenhagen, Copenhagen, Denmark
- Burnet Institute, Melbourne, Victoria, Australia
| | - Dina Mistry
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | | | - Katherine Rosenfeld
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Gregory R. Hart
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Rafael C. Núñez
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Jamie A. Cohen
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Prashanth Selvaraj
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Brittany Hagedorn
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Lauren George
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | | | - Amanda S. Izzo
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Greer Fowler
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Anna Palmer
- Burnet Institute, Melbourne, Victoria, Australia
| | | | - Nick Scott
- Burnet Institute, Melbourne, Victoria, Australia
| | | | - Caroline S. Bennette
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Bradley G. Wagner
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Stewart T. Chang
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Assaf P. Oron
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Edward A. Wenger
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Jasmina Panovska-Griffiths
- Big Data Institute, University of Oxford, Oxford, United Kingdom
- Wolfson Centre for Mathematical Biology and The Queen’s College, University of Oxford, Oxford, United Kingdom
| | - Michael Famulare
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Daniel J. Klein
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
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Kerr CC, Mistry D, Stuart RM, Rosenfeld K, Hart GR, Núñez RC, Cohen JA, Selvaraj P, Abeysuriya RG, Jastrzębski M, George L, Hagedorn B, Panovska-Griffiths J, Fagalde M, Duchin J, Famulare M, Klein DJ. Controlling COVID-19 via test-trace-quarantine. Nat Commun 2021; 12:2993. [PMID: 34017008 PMCID: PMC8137690 DOI: 10.1038/s41467-021-23276-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 04/21/2021] [Indexed: 02/07/2023] Open
Abstract
Initial COVID-19 containment in the United States focused on limiting mobility, including school and workplace closures. However, these interventions have had enormous societal and economic costs. Here, we demonstrate the feasibility of an alternative control strategy, test-trace-quarantine: routine testing of primarily symptomatic individuals, tracing and testing their known contacts, and placing their contacts in quarantine. We perform this analysis using Covasim, an open-source agent-based model, which has been calibrated to detailed demographic, mobility, and epidemiological data for the Seattle region from January through June 2020. With current levels of mask use and schools remaining closed, we find that high but achievable levels of testing and tracing are sufficient to maintain epidemic control even under a return to full workplace and community mobility and with low vaccine coverage. The easing of mobility restrictions in June 2020 and subsequent scale-up of testing and tracing programs through September provided real-world validation of our predictions. Although we show that test-trace-quarantine can control the epidemic in both theory and practice, its success is contingent on high testing and tracing rates, high quarantine compliance, relatively short testing and tracing delays, and moderate to high mask use. Thus, in order for test-trace-quarantine to control transmission with a return to high mobility, strong performance in all aspects of the program is required.
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Affiliation(s)
- Cliff C Kerr
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA.
| | - Dina Mistry
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Robyn M Stuart
- Department of Mathematical Sciences, University of Copenhagen, Copenhagen, Denmark
- Burnet Institute, Melbourne, VIC, Australia
| | - Katherine Rosenfeld
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Gregory R Hart
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Rafael C Núñez
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Jamie A Cohen
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Prashanth Selvaraj
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | | | | | - Lauren George
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Brittany Hagedorn
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Jasmina Panovska-Griffiths
- Department of Applied Health Research, University College London, London, UK
- Wolfson Centre for Mathematical Biology and The Queen's College, Oxford University, Oxford, UK
| | | | | | - Michael Famulare
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Daniel J Klein
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
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11
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Kerr CC, Mistry D, Stuart RM, Rosenfeld K, Hart GR, Núñez RC, Cohen JA, Selvaraj P, Abeysuriya RG, Jastrzębski M, George L, Hagedorn B, Panovska-Griffiths J, Fagalde M, Duchin J, Famulare M, Klein DJ. Controlling COVID-19 via test-trace-quarantine. Nat Commun 2021. [PMID: 34017008 DOI: 10.1101/2020.07.15.20154765] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023] Open
Abstract
Initial COVID-19 containment in the United States focused on limiting mobility, including school and workplace closures. However, these interventions have had enormous societal and economic costs. Here, we demonstrate the feasibility of an alternative control strategy, test-trace-quarantine: routine testing of primarily symptomatic individuals, tracing and testing their known contacts, and placing their contacts in quarantine. We perform this analysis using Covasim, an open-source agent-based model, which has been calibrated to detailed demographic, mobility, and epidemiological data for the Seattle region from January through June 2020. With current levels of mask use and schools remaining closed, we find that high but achievable levels of testing and tracing are sufficient to maintain epidemic control even under a return to full workplace and community mobility and with low vaccine coverage. The easing of mobility restrictions in June 2020 and subsequent scale-up of testing and tracing programs through September provided real-world validation of our predictions. Although we show that test-trace-quarantine can control the epidemic in both theory and practice, its success is contingent on high testing and tracing rates, high quarantine compliance, relatively short testing and tracing delays, and moderate to high mask use. Thus, in order for test-trace-quarantine to control transmission with a return to high mobility, strong performance in all aspects of the program is required.
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Affiliation(s)
- Cliff C Kerr
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA.
| | - Dina Mistry
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Robyn M Stuart
- Department of Mathematical Sciences, University of Copenhagen, Copenhagen, Denmark
- Burnet Institute, Melbourne, VIC, Australia
| | - Katherine Rosenfeld
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Gregory R Hart
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Rafael C Núñez
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Jamie A Cohen
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Prashanth Selvaraj
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | | | | | - Lauren George
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Brittany Hagedorn
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Jasmina Panovska-Griffiths
- Department of Applied Health Research, University College London, London, UK
- Wolfson Centre for Mathematical Biology and The Queen's College, Oxford University, Oxford, UK
| | | | | | - Michael Famulare
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Daniel J Klein
- Institute for Disease Modeling, Global Health Division, Bill & Melinda Gates Foundation, Seattle, WA, USA
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12
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Skrip LA, Selvaraj P, Hagedorn B, Ouédraogo AL, Noori N, Orcutt A, Mistry D, Bedson J, Hébert-Dufresne L, Scarpino SV, Althouse BM. Seeding COVID-19 across Sub-Saharan Africa: An Analysis of Reported Importation Events across 49 Countries. Am J Trop Med Hyg 2021; 104:1694-1702. [PMID: 33684067 PMCID: PMC8103462 DOI: 10.4269/ajtmh.20-1502] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 02/01/2021] [Indexed: 01/10/2023] Open
Abstract
The first case of COVID-19 in sub-Saharan Africa (SSA) was reported by Nigeria on February 27, 2020. Whereas case counts in the entire region remain considerably less than those being reported by individual countries in Europe, Asia, and the Americas, variation in preparedness and response capacity as well as in data availability has raised concerns about undetected transmission events in the SSA region. To capture epidemiological details related to early transmission events into and within countries, a line list was developed from publicly available data on institutional websites, situation reports, press releases, and social media accounts. The availability of indicators-gender, age, travel history, date of arrival in country, reporting date of confirmation, and how detected-for each imported case was assessed. We evaluated the relationship between the time to first reported importation and the Global Health Security Index (GHSI) overall score; 13,201 confirmed cases of COVID-19 were reported by 48 countries in SSA during the 54 days following the first known introduction to the region. Of the 2,516 cases for which travel history information was publicly available, 1,129 (44.9%) were considered importation events. Imported cases tended to be male (65.0%), with a median age of 41.0 years (range: 6 weeks-88 years; IQR: 31-54 years). A country's time to report its first importation was not related to the GHSI overall score, after controlling for air traffic. Countries in SSA generally reported with less publicly available detail over time and tended to have greater information on imported than local cases.
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Affiliation(s)
- Laura A. Skrip
- Institute for Disease Modeling, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Prashanth Selvaraj
- Institute for Disease Modeling, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Brittany Hagedorn
- Institute for Disease Modeling, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Andre Lin Ouédraogo
- Institute for Disease Modeling, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Navideh Noori
- Institute for Disease Modeling, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Amanda Orcutt
- Institute for Disease Modeling, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Dina Mistry
- Institute for Disease Modeling, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Jamie Bedson
- Consultant to the Bill & Melinda Gates Foundation, Seattle, Washington
| | - Laurent Hébert-Dufresne
- Department of Computer Science, Vermont Complex Systems Center, University of Vermont, Burlington, Vermont;,Department of Computer Science, University of Vermont, Burlington, Vermont
| | - Samuel V. Scarpino
- Network Science Institute, Northeastern University, Boston, Massachusetts;,Department of Marine and Environmental Sciences, Northeastern University, Boston, Massachusetts;,Department of Physics, Northeastern University, Boston, Massachusetts;,Department of Health Sciences, Northeastern University, Boston, Massachusetts;,ISI Foundation, Turin, Italy
| | - Benjamin M. Althouse
- Institute for Disease Modeling, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington;,University of Washington, Seattle, Washington;,New Mexico State University, Las Cruces, New Mexico,Address correspondence to Benjamin M. Althouse, Institute for Disease Modeling, Global Health Division Bill & Melinda Gates Foundation, 500 5th Ave. N, Seattle, WA 98109. E-mail:
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13
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Bousema T, Selvaraj P, Djimde AA, Yakar D, Hagedorn B, Pratt A, Barret D, Whitfield K, Cohen JM. Reducing the Carbon Footprint of Academic Conferences: The Example of the American Society of Tropical Medicine and Hygiene. Am J Trop Med Hyg 2020; 103:1758-1761. [PMID: 33069267 PMCID: PMC7646750 DOI: 10.4269/ajtmh.20-1013] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We calculated carbon emissions associated with air travel of 4,834 participants at the 2019 annual conference of the American Society of Tropical Medicine and Hygiene (ASTMH). Together, participants traveled a total of 27.7 million miles or 44.6 million kilometers. This equates to 58 return trips to the moon. Estimated carbon dioxide equivalent (CO2e) emissions were 8,646 metric tons or the total weekly carbon footprint of approximately 9,366 average American households. These emissions contribute to climate change and thus may exacerbate many of the global diseases that conference attendees seek to combat. Options to reduce conference travel-associated emissions include 1) alternating in-person and online conferences, 2) offering a hybrid in-person/online conference, and 3) decentralizing the conference with multiple conference venues. Decentralized ASTMH conferences may allow for up to 64% reduction in travel distance and 58% reduction in CO2e emissions. Given the urgency of the climate crisis and the clear association between global warming and global health, ways to reduce carbon emissions should be considered.
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Affiliation(s)
- Teun Bousema
- Department of Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | | | - Abdoulaye A Djimde
- University of Science, Techniques and Technology of Bamako, Bamako, Mali
| | - Derya Yakar
- Department of Radiology, University Medical Center Groningen, Groningen, The Netherlands
| | | | - Abigail Pratt
- Bill & Melinda Gates Foundation, Seattle, Washington
| | - Didier Barret
- Institut de Recherche en Astrophysique et Planétologie, Centre National de la Recherche Scientifique, Toulouse, France
| | - Kate Whitfield
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
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14
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Skrip L, Derra K, Kaboré M, Noori N, Gansané A, Valéa I, Tinto H, Brice BW, Gordon MV, Hagedorn B, Hien H, Althouse BM, Wenger EA, Ouédraogo AL. Clinical management and mortality among COVID-19 cases in sub-Saharan Africa: A retrospective study from Burkina Faso and simulated case analysis. Int J Infect Dis 2020; 101:194-200. [PMID: 32987177 PMCID: PMC7518969 DOI: 10.1016/j.ijid.2020.09.1432] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/13/2020] [Accepted: 09/22/2020] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Absolute numbers of COVID-19 cases and deaths reported to date in the sub-Saharan Africa (SSA) region have been significantly lower than those across the Americas, Asia and Europe. As a result, there has been limited information about the demographic and clinical characteristics of deceased cases in the region, as well as the impacts of different case management strategies. METHODS Data from deceased cases reported across SSA through 10 May 2020 and from hospitalized cases in Burkina Faso through 15 April 2020 were analyzed. Demographic, epidemiological and clinical information on deceased cases in SSA was derived through a line-list of publicly available information and, for cases in Burkina Faso, from aggregate records at the Centre Hospitalier Universitaire de Tengandogo in Ouagadougou. A synthetic case population was probabilistically derived using distributions of age, sex and underlying conditions from populations of West African countries to assess individual risk factors and treatment effect sizes. Logistic regression analysis was conducted to evaluate the adjusted odds of survival for patients receiving oxygen therapy or convalescent plasma, based on therapeutic effectiveness observed for other respiratory illnesses. RESULTS Across SSA, deceased cases for which demographic data were available were predominantly male (63/103, 61.2%) and aged >50 years (59/75, 78.7%). In Burkina Faso, specifically, the majority of deceased cases either did not seek care at all or were hospitalized for a single day (59.4%, 19/32). Hypertension and diabetes were often reported as underlying conditions. After adjustment for sex, age and underlying conditions in the synthetic case population, the odds of mortality for cases not receiving oxygen therapy were significantly higher than for those receiving oxygen, such as due to disruptions to standard care (OR 2.07; 95% CI 1.56-2.75). Cases receiving convalescent plasma had 50% reduced odds of mortality than those who did not (95% CI 0.24-0.93). CONCLUSIONS Investment in sustainable production and maintenance of supplies for oxygen therapy, along with messaging around early and appropriate use for healthcare providers, caregivers and patients could reduce COVID-19 deaths in SSA. Further investigation into convalescent plasma is warranted until data on its effectiveness specifically in treating COVID-19 becomes available. The success of supportive or curative clinical interventions will depend on earlier treatment seeking, such that community engagement and risk communication will be critical components of the response.
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Affiliation(s)
- Laura Skrip
- Institute for Disease Modeling, Bellevue, WA, USA.
| | - Karim Derra
- IRSS-Clinical Research Unit of Nanoro, Burkina Faso
| | - Mikaila Kaboré
- Ministry of Health, Teaching Hospital Yalgado Ouedraogo, Ouagadougou, Burkina Faso
| | | | - Adama Gansané
- Centre National de Recherche et de Formation Sur le Paludisme, National Public Health Institute, Ouagadougou, Burkina Faso
| | | | | | - Bicaba W Brice
- Centre des Operations de Réponses aux Urgences Sanitaires, Ouagadougou, National Public Health Institute, Burkina Faso
| | | | | | - Hervé Hien
- Centre MURAZ, National Public Health Institute, Ouagadougou, Burkina Faso; IRSS, Programme de Recherche Sur les Politiques et les Systèmes de Santé, Bobo-Dioulasso, Burkina Faso
| | - Benjamin M Althouse
- Institute for Disease Modeling, Bellevue, WA, USA; University of Washington, Seattle, WA, USA; New Mexico State University, Las Cruces, NM, USA
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15
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Zimmermann M, Hagedorn B, Lyons H. Projection of Costs of Polio Eradication Compared to Permanent Control. J Infect Dis 2020; 221:561-565. [PMID: 31565733 DOI: 10.1093/infdis/jiz488] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/25/2019] [Indexed: 11/12/2022] Open
Abstract
Despite increased efforts and spending toward polio eradication, it has yet to be eliminated worldwide. We aimed to project economic costs of polio eradication compared to permanent control. We used historical Financial Resource Requirements from the Global Polio Eradication Initiative, as well as vaccination and population data from publicly available sources, to project costs for routine immunization, immunization campaigns, surveillance and laboratory resources, technical assistance, social mobilization, treatment, and overhead. We found that cumulative spending for a control strategy would exceed that for an eradication strategy in 2032 (range, 2027-2051). Eradication of polio would likely be cost-saving compared to permanent control.
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Affiliation(s)
- Marita Zimmermann
- Global Development Research, Institute for Disease Modeling, Bellevue, Washington
| | - Brittany Hagedorn
- Global Development Research, Institute for Disease Modeling, Bellevue, Washington
| | - Hil Lyons
- Global Development Research, Institute for Disease Modeling, Bellevue, Washington
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16
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Willershausen B, Hagedorn B, Tekyatan H, Briseño Marroquín B. Effect of calcium hydroxide and chlorhexidine based gutta-percha points on gingival fibroblasts and epithelial tumor cells. Eur J Med Res 2004; 9:345-50. [PMID: 15337635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023] Open
Abstract
AIMS AND METHODS The aim of the present study was to demonstrate the possible effect of different endodontic calcium hydroxide and chlorhexidine-based gutta-percha points, on two different human cell culture systems. Two different calcium hydroxide (Roeko, Langenau, Germany) and one chlorhexidine (Activ Point/Roeko, Langenau, Germany) gutta-percha points were tested with gingival fibroblasts and epithelial tumor cells over a period of six days (n = 12). Conventional gutta-percha points (VDW, Munich, Germany) and cells that were not exposed to any substances served as controls (n = 12). Study parameters included cell vitality, cell count, protein synthesis and cell proliferation. RESULTS All tested materials induced cell growth specific alterations. Chlorhexidine-based gutta-percha points showed a significant lower protein synthesis with both, gingival fibroblasts (0.013 +/- 0.009 mg/ml) and epithelial tumor cells (0.07 +/- 0.039 mg/ml), when compared with the controls (p > 0.05). Protein synthesis increase of the epithelial tumor cells (0.581 +/- 0.013 mg/ml, control) was observed with the conventional gutta-percha points (0.688 +/- 0.078 mg/ml) and with both gutta-percha points containing different calcium hydroxide-based formulations (0.776 +/- 0.115 and 0.7 +/- 0.047 mg/ ml). CONCLUSIONS Under the conditions of this study, chlorhexidine containing gutta-percha points showed the highest effect on cell growth inhibition. No significant differences were observed between the tested material and the two different cell culture types.
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Affiliation(s)
- B Willershausen
- Department for Operative Dentistry, Johannes Gutenberg University-Mainz, Germany.
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17
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Hagedorn B, Willershausen B, Ernst CP, Wehse T, Schimmel M. A comparative study of 2 fluoride-based mouthrinses. Quintessence Int 2000; 31:125-8. [PMID: 11203913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
OBJECTIVE The purpose of this study was to compare the effectiveness of 2 mouthrinses (conventional Meridol and alcohol-free Meridol). METHOD AND MATERIALS A controlled, single-blind clinical study of 3 weeks' duration was conducted on 80 adult subjects in good general health and without severe periodontitis (probing depths no deeper than 4 mm). The mouthrinses supplemented regular measures of oral hygiene for the reduction of plaque and gingivitis. In preliminary examinations to determine general conditions of oral health, especially the level of plaque, gingivitis, and periodontal findings, the approximal plaque index, sulcular bleeding index, and gingival index were established for each subject. Afterward the subjects were provided with a professional toothcleaning, as required. Each subject was randomly provided with 1 of the 2 mouthrinses, to be used 3 times daily in addition to routine oral health measures. The 3 indexes were reevaluated after 3 weeks; in addition, an optional stain index was employed. RESULTS In both subject groups, a statistically significant reduction in plaque accumulation, as well as a reduction in inflammation and the tendency to bleeding, was observed. Reversible staining of the teeth and tongue was observed in fewer than one third of the subjects in both groups. CONCLUSION Comparison of the 2 Meridol mouthrinses revealed no difference in effectiveness related to the alcohol content.
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Affiliation(s)
- B Hagedorn
- Department of Restorative Dentistry and Periodontology, Johannes Gutenberg-University of Mainz, Langenbeckstrasse 1, 55101 Mainz, Germany
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18
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Willershausen B, Lenzner K, Hagedorn B, Ernst C. Oral health status of hospitalized children with cancer: a comparative study. Eur J Med Res 1998; 3:480-4. [PMID: 9753706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
In this study, oral findings from children suffering from leukemia or other cancers, and hospitalized for treatments, are compared with findings from hospitalized patients from the Children s Surgery Department, without systemic or general illnesses. The aim of the study is to determine possible differences in the status of oral health between the hospitalized cancer-ward children and children hospitalized, but with good general health, in order to develop special prophylactic measures as required. The visual oral findings included the prevalence of caries (DMF/T, Decayed, Missed, Filled/Tooth), oral hygiene, severe periodontal diseases, records of defects of the oral mucosa, and information was collected on fluoridation. For both groups of children, the degree of treatment-need of the remaining dentition was 63%. Caries-free dentition was found in 53.7% of the surgery patients and 40.7% of the cancer-ward children. Good oral hygiene was found in only 49% of the cases among the cancer-ward children, while among the children without systemic illness the figure climbed to 87% of the cases. Gingivitis among the children without general illness was only diagnosed in 7.4% of the cases, but in contrast, among the cancer-ward children the percentage of gingivitis (62.8% ) was significantly higher (p < 0.0001). The present study strongly suggests that for children with cancer and subject to aggressive therapy and/or long hospitalizations, beyond the general medical examination on hospital admission, a dental examination should also be instituted.
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Affiliation(s)
- B Willershausen
- Department of Restorative Dentistry and Periodontology, Johannes Gutenberg-University Mainz, Augustusplatz 2, D-55131 Mainz, Germany.
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Hagedorn B, Kostenbauder HB. Studies on the effect of tobacco smoke on the biotransformation of vasoactive substances in the isolated perfused rabbit lung. II. Angiotensin I conversion. Res Commun Chem Pathol Pharmacol 1978; 20:195-8. [PMID: 663403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Cigarette smoke administration was previously found to have a pronounced inhibitory effect on metabolism of nicotine and benzo[a]pyrene in the isolated perfused rabbit lung. These observations suggest the possibility of tobacco smoke inhibition of biotransformations associated with non-ventilatory pulmonary functions such as the biotransformation of endogenous vasoactive substances. However, the present study provides no evidence of an effect of smoke on the conversion of angiotensin I to angiotensin II in the isolated perfused rabbit lung.
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Hagedorn B, Kostenbauder HB. Studies on the effect of tobacco smoke on the biotransformation of vasoactive substances in the isolated perfused rabbit lung. I. Prostaglandin F2alpha. Res Commun Chem Pathol Pharmacol 1977; 18:495-506. [PMID: 928950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cigarette smoke administration was previously found to have a pronounced inhibitory effect on metabolism of nicotine and benzo[a]pyrene in the isolated perfused rabbit lung. These observations suggest the possibility of tobacco smoke inhibition of biotransformations associated with non-ventilatory pulmonary functions such as metabolic clearance of endogenous vasoactive substances. However, studies of the effect of smoke on uptake and metabolism of PGF2alpha in isolated perfused rabbit lungs provide no evidence of inhibition of these processes.
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Hagedorn B. Von Willebrand's disease. JAMA 1971; 216:991-5. [PMID: 4929581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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