APS Bulletin of the American Physical Society. 2005 APS March Meeting. MondayFriday, March 2125... more APS Bulletin of the American Physical Society. 2005 APS March Meeting. MondayFriday, March 2125, 2005; Los Angeles, CA. ...
Background During a pandemic, public health authorities must make critical real-time intervention... more Background During a pandemic, public health authorities must make critical real-time intervention decisions, often in the face of considerable uncertainty about the magnitude and severity of the pandemic. Preparedness plans and real-time decision support tools are thus essential to pandemic readiness. In collaboration with the Texas Department of State Health Services, we developed an interactive pandemic toolkit to aid in influenza preparedness and response. The toolkit includes a data-driven, individual-level influenza simulator, as well as decision-support modules for antiviral, vaccine and ventilator distributions. This presentation will demonstrate these tools and address the extendibility of this toolkit to other regions. Objective To develop an interactive, real-time environment for simulating pandemic influenza, assessing public health intervention strategies, and designing surveillance networks. Methods The Pandemic Exercise Tool has two primary components. The first compon...
Contact network models are a flexible approach for investigating disease dynamics, and have provi... more Contact network models are a flexible approach for investigating disease dynamics, and have provided epidemiological insight across a wide range of wild animal social systems. While flexible and powerful, this methodology is hampered by lack of detailed contact data. I will discuss traditional and new technology based strategies for collecting sufficient behavioral data from raccoons to African lions, and the utility of modeling contact patterns in wild animal populations.
Networks are widely used in science and technology to represent relationships between entities, s... more Networks are widely used in science and technology to represent relationships between entities, such as social or ecological links between organisms, enzymatic interactions in metabolic systems, or computer infrastructure. Statistical analyses of networks can provide critical insights into the structure, function, dynamics, and evolution of those systems. However, the structures of real-world networks are often not known completely, and they may exhibit considerable variation so that no single network is sufficiently representative of a system. In such situations, researchers may turn to proxy data from related systems, sophisticated methods for network inference, or synthetic networks. Here, we introduce a flexible method for synthesizing realistic ensembles of networks starting from a known network, through a series of mappings that coarsen and later refine the network structure by randomized editing. The method, MUSKETEER, preserves structural properties with minimal bias, includ...
Multiple waves of transmission during infectious disease epidemics represent a major public healt... more Multiple waves of transmission during infectious disease epidemics represent a major public health challenge, but the ecological and behavioral drivers of epidemic resurgence are poorly understood. In theory, community structure-aggregation into highly intraconnected and loosely interconnected social groups-within human populations may lead to punctuated outbreaks as diseases progress from one community to the next. However, this explanation has been largely overlooked in favor of temporal shifts in environmental conditions and human behavior and because of the difficulties associated with estimating large-scale contact patterns. The aim was to characterize naturally arising patterns of human contact that are capable of producing simulated epidemics with multiple wave structures. We used an extensive dataset of proximal physical contacts between users of a public Wi-Fi Internet system to evaluate the epidemiological implications of an empirical urban contact network. We characterize...
As a devastating Ebola outbreak in West Africa continues, non-pharmaceutical control measures inc... more As a devastating Ebola outbreak in West Africa continues, non-pharmaceutical control measures including contact tracing, quarantine, and case isolation are being implemented. In addition, public health agencies are scaling up efforts to test and deploy candidate vaccines. Given the experimental nature and limited initial supplies of vaccines, a mass vaccination campaign might not be feasible. However, ring vaccination of likely case contacts could provide an effective alternative in distributing the vaccine. To evaluate ring vaccination as a strategy for eliminating Ebola, we developed a pair approximation model of Ebola transmission, parameterized by confirmed incidence data from June 2014 to January 2015 in Liberia and Sierra Leone. Our results suggest that if a combined intervention of case isolation and ring vaccination had been initiated in the early fall of 2014, up to an additional 126 cases in Liberia and 560 cases in Sierra Leone could have been averted beyond case isolatio...
Safe and effective vaccines could help to end the ongoing Ebola virus disease epidemic in parts o... more Safe and effective vaccines could help to end the ongoing Ebola virus disease epidemic in parts of west Africa, and mitigate future outbreaks of the virus. We assess the statistical validity and power of randomised controlled trial (RCT) and stepped-wedge cluster trial (SWCT) designs in Sierra Leone, where the incidence of Ebola virus disease is spatiotemporally heterogeneous, and is decreasing rapidly. We projected district-level Ebola virus disease incidence for the next 6 months, using a stochastic model fitted to data from Sierra Leone. We then simulated RCT and SWCT designs in trial populations comprising geographically distinct clusters at high risk, taking into account realistic logistical constraints, and both individual-level and cluster-level variations in risk. We assessed false-positive rates and power for parametric and non-parametric analyses of simulated trial data, across a range of vaccine efficacies and trial start dates. For an SWCT, regional variation in Ebola virus disease incidence trends produced increased false-positive rates (up to 0·15 at α=0·05) under standard statistical models, but not when analysed by a permutation test, whereas analyses of RCTs remained statistically valid under all models. With the assumption of a 6-month trial starting on Feb 18, 2015, we estimate the power to detect a 90% effective vaccine to be between 49% and 89% for an RCT, and between 6% and 26% for an SWCT, depending on the Ebola virus disease incidence within the trial population. We estimate that a 1-month delay in trial initiation will reduce the power of the RCT by 20% and that of the SWCT by 49%. Spatiotemporal variation in infection risk undermines the statistical power of the SWCT. This variation also undercuts the SWCT's expected ethical advantages over the RCT, because an RCT, but not an SWCT, can prioritise vaccination of high-risk clusters. US National Institutes of Health, US National Science Foundation, and Canadian Institutes of Health Research.
APS Bulletin of the American Physical Society. 2005 APS March Meeting. MondayFriday, March 2125... more APS Bulletin of the American Physical Society. 2005 APS March Meeting. MondayFriday, March 2125, 2005; Los Angeles, CA. ...
Background During a pandemic, public health authorities must make critical real-time intervention... more Background During a pandemic, public health authorities must make critical real-time intervention decisions, often in the face of considerable uncertainty about the magnitude and severity of the pandemic. Preparedness plans and real-time decision support tools are thus essential to pandemic readiness. In collaboration with the Texas Department of State Health Services, we developed an interactive pandemic toolkit to aid in influenza preparedness and response. The toolkit includes a data-driven, individual-level influenza simulator, as well as decision-support modules for antiviral, vaccine and ventilator distributions. This presentation will demonstrate these tools and address the extendibility of this toolkit to other regions. Objective To develop an interactive, real-time environment for simulating pandemic influenza, assessing public health intervention strategies, and designing surveillance networks. Methods The Pandemic Exercise Tool has two primary components. The first compon...
Contact network models are a flexible approach for investigating disease dynamics, and have provi... more Contact network models are a flexible approach for investigating disease dynamics, and have provided epidemiological insight across a wide range of wild animal social systems. While flexible and powerful, this methodology is hampered by lack of detailed contact data. I will discuss traditional and new technology based strategies for collecting sufficient behavioral data from raccoons to African lions, and the utility of modeling contact patterns in wild animal populations.
Networks are widely used in science and technology to represent relationships between entities, s... more Networks are widely used in science and technology to represent relationships between entities, such as social or ecological links between organisms, enzymatic interactions in metabolic systems, or computer infrastructure. Statistical analyses of networks can provide critical insights into the structure, function, dynamics, and evolution of those systems. However, the structures of real-world networks are often not known completely, and they may exhibit considerable variation so that no single network is sufficiently representative of a system. In such situations, researchers may turn to proxy data from related systems, sophisticated methods for network inference, or synthetic networks. Here, we introduce a flexible method for synthesizing realistic ensembles of networks starting from a known network, through a series of mappings that coarsen and later refine the network structure by randomized editing. The method, MUSKETEER, preserves structural properties with minimal bias, includ...
Multiple waves of transmission during infectious disease epidemics represent a major public healt... more Multiple waves of transmission during infectious disease epidemics represent a major public health challenge, but the ecological and behavioral drivers of epidemic resurgence are poorly understood. In theory, community structure-aggregation into highly intraconnected and loosely interconnected social groups-within human populations may lead to punctuated outbreaks as diseases progress from one community to the next. However, this explanation has been largely overlooked in favor of temporal shifts in environmental conditions and human behavior and because of the difficulties associated with estimating large-scale contact patterns. The aim was to characterize naturally arising patterns of human contact that are capable of producing simulated epidemics with multiple wave structures. We used an extensive dataset of proximal physical contacts between users of a public Wi-Fi Internet system to evaluate the epidemiological implications of an empirical urban contact network. We characterize...
As a devastating Ebola outbreak in West Africa continues, non-pharmaceutical control measures inc... more As a devastating Ebola outbreak in West Africa continues, non-pharmaceutical control measures including contact tracing, quarantine, and case isolation are being implemented. In addition, public health agencies are scaling up efforts to test and deploy candidate vaccines. Given the experimental nature and limited initial supplies of vaccines, a mass vaccination campaign might not be feasible. However, ring vaccination of likely case contacts could provide an effective alternative in distributing the vaccine. To evaluate ring vaccination as a strategy for eliminating Ebola, we developed a pair approximation model of Ebola transmission, parameterized by confirmed incidence data from June 2014 to January 2015 in Liberia and Sierra Leone. Our results suggest that if a combined intervention of case isolation and ring vaccination had been initiated in the early fall of 2014, up to an additional 126 cases in Liberia and 560 cases in Sierra Leone could have been averted beyond case isolatio...
Safe and effective vaccines could help to end the ongoing Ebola virus disease epidemic in parts o... more Safe and effective vaccines could help to end the ongoing Ebola virus disease epidemic in parts of west Africa, and mitigate future outbreaks of the virus. We assess the statistical validity and power of randomised controlled trial (RCT) and stepped-wedge cluster trial (SWCT) designs in Sierra Leone, where the incidence of Ebola virus disease is spatiotemporally heterogeneous, and is decreasing rapidly. We projected district-level Ebola virus disease incidence for the next 6 months, using a stochastic model fitted to data from Sierra Leone. We then simulated RCT and SWCT designs in trial populations comprising geographically distinct clusters at high risk, taking into account realistic logistical constraints, and both individual-level and cluster-level variations in risk. We assessed false-positive rates and power for parametric and non-parametric analyses of simulated trial data, across a range of vaccine efficacies and trial start dates. For an SWCT, regional variation in Ebola virus disease incidence trends produced increased false-positive rates (up to 0·15 at α=0·05) under standard statistical models, but not when analysed by a permutation test, whereas analyses of RCTs remained statistically valid under all models. With the assumption of a 6-month trial starting on Feb 18, 2015, we estimate the power to detect a 90% effective vaccine to be between 49% and 89% for an RCT, and between 6% and 26% for an SWCT, depending on the Ebola virus disease incidence within the trial population. We estimate that a 1-month delay in trial initiation will reduce the power of the RCT by 20% and that of the SWCT by 49%. Spatiotemporal variation in infection risk undermines the statistical power of the SWCT. This variation also undercuts the SWCT's expected ethical advantages over the RCT, because an RCT, but not an SWCT, can prioritise vaccination of high-risk clusters. US National Institutes of Health, US National Science Foundation, and Canadian Institutes of Health Research.
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Papers by Lauren Meyers