scholarly journals Comparison of epidemic control strategies using agent-based simulations

2020 ◽  
Author(s):  
Pablo Martínez Ruiz del Árbol ◽  
Lara Lloret Iglesias
Keyword(s):  
Control Strategies ◽  
Large Fraction ◽  
Small Population ◽  
Graph Database ◽  
Epidemic Control ◽  
Agent Based ◽  
Testing Strategies ◽  
Basic Parameters ◽  
The Cost ◽  
The Impact

AbstractA simulation of the dynamics of a small population is used to assess the impact of different confinement and testing strategies in the control of an epidemic. The simulation considers individuals as agents moving randomly across the habitat according to predefined urban patterns. Agents carry a simple tracing device that identifies signals emitted by other agents, recording the position and time of the encounter. The information of every device is propagated daily to an epidemic observatory based on an online graph database. Infections are simulated as stochastic processes depending on the proximity among individuals. Different epidemic control strategies are tested with and without the information of the tracing device under several scenarios. We observe that the success of the strategies strongly depends on the duration of the period of infectiousness before the presence of symptoms and the fraction of asymptomatic agents. If these values are high, strategies based on the presence of symptoms or on testing campaigns can hardly contain the epidemic. Strategies using massive confinement of the agents are able to control the epidemic at the cost of sending a large fraction of the population into quarantine. In cases with moderate and low values for these parameters, the tracing devices can provide a slightly better performance but only if a large fraction of the agents carry the device. Otherwise, the impact of these devices is found to be negligible in comparison with other strategies not using them. Finally, we provide a methodology allowing to use the information of the graph database to estimate basic parameters of the disease such as the infection probability.

The Impact of Military Spending on Economic Development

2018 ◽  
pp. 182-191
Author(s):  
Saptarshi Chakraborty
Keyword(s):  
Economic Growth ◽  
Causal Effect ◽  
Large Fraction ◽  
Military Spending ◽  
Military Expenditure ◽  
Policy Debate ◽  
External Threats ◽  
The Cost ◽  
The Military ◽  
The Impact

Some countries spend a relatively large percentage of GDP on their militaries in order to preserve or secure their status as global powers. Others do so because they are ruled by military governments or aggressive regimes that pose a military threat to their neighbors or their own populations. It is debatable whether there is a causal relationship between military spending and economic growth in the economy. It is again a policy debate how much to allocate funds for civilian and how much for military expenditure. Under these puzzling results of the impact of military expenditure on economic growth which is frequently found to be non-significant or negative, yet most countries spend a large fraction of their GDP on defense and the military. The chapter tries to investigate the relationship between military spending and economic growth in India. It also sees whether external threats, corruption, and other relevant controls have any causal effect. This chapter obtains that additional expenditure on Indian military in the presence of additional threat is significantly detrimental to growth implying that India cannot afford to fight or demonstrate power at the cost of its development.

Assessing the Impact of Temperature Change on the Effectiveness of Insecticide-Treated Nets

2011 ◽  
Vol 3 (3) ◽  
pp. 35-48 ◽  
Author(s):  
Gregory J. Davis
Keyword(s):  
Control Strategies ◽  
Global Climate ◽  
Financial Burden ◽  
Insecticide Treated Nets ◽  
Policy Makers ◽  
Agent Based ◽  
Mosquito Abundance ◽  
Vector Borne ◽  
And Control ◽  
The Impact

Malaria is a vector-borne illness affecting millions of lives annually and imposes a heavy financial burden felt worldwide. Moreover, there is growing concern that global climate change, in particular, rising temperature, will increase this burden. As such, policy makers are in need of tools capable of informing them about the potential strengths and weaknesses of intervention and control strategies. A previously developed agent-based model of the Anopheles gambiae mosquito is extended, one of the primary vectors of malaria, to investigate how changes in temperature influence the dynamics of malaria transmission and the effectiveness of a common malaria intervention: insecticide-treated nets (ITNs). Results from the simulations suggest two important findings. Consistent with previous studies, an increase in mosquito abundance as temperature increases is observed. However, the increase in mosquito abundance reduces the effectiveness of ITNs at a given coverage level. The implications and limitations of these findings are discussed.

scholarly journals COVID-19 effective reproductive ratio determination: An application, and analysis of issues and influential factors

2020 ◽  
Author(s):  
Luis Alfredo Bautista Balbás ◽  
Mario Gil Conesa ◽  
Gil Rodríguez Caravaca ◽  
Blanca Bautista Balbás
Keyword(s):  
Web Application ◽  
Control Strategies ◽  
Infected Individual ◽  
National Level ◽  
Open Data ◽  
Conclusive Evidence ◽  
Influential Factors ◽  
Mitigation Strategies ◽  
Epidemic Control ◽  
The Impact

An essential indicator of COVID-19 transmission is the effective reproduction number (Rt), the number of cases which an infected individual is expected to infect at a particular moment of time; curves of the evolution of Rt over time (transmission curves) reflect the impact of preventive measures and whether an epidemic is controlled. We have created a Shiny/R web application with user-selectable features: open data sources with daily COVID-19 incidences from all countries and many regions, customizable preprocessing options (smoothing, proportional increment, backwards distribution of negative corrections, etc), different MonteCarlo-Markov-Chain estimates of the generation time or serial interval distributions and state-of-the-art Rt estimation frameworks (EpiEstim, R0). We have analyzed the impact of these factors in the obtained transmission curves. We also have obtained curves at the national and sub-national level and analyzed the impact of epidemic control strategies, superspreading events, socioeconomic factors and outbreaks. We conclude that country wealth and, to a lesser extent, mitigation strategies, were associated with poorer epidemic control. Dataset quality was an important factor, and sometimes dictated the necessity of time series smoothing. We couldn't find conclusive evidence regarding the impact of alleged superspreading events. In the reopening phase, outbreaks had an impact on transmission curves. This application could be used interactively as a tool both to obtain transmission estimates and to perform interactive sensitivity analysis.

scholarly journals Comparative Impact of Individual Quarantine vs. Active Monitoring of Contacts for the Mitigation of COVID-19: a modelling study

2020 ◽  
Author(s):  
Corey M. Peak ◽  
Rebecca Kahn ◽  
Yonatan H. Grad ◽  
Lauren M. Childs ◽  
Ruoran Li ◽  
...  
Keyword(s):  
Control Strategies ◽  
Emerging Infectious Diseases ◽  
Cost Benefit ◽  
Mitigation Measures ◽  
Individual Liberty ◽  
Average Delay ◽  
Active Monitoring ◽  
Serial Interval ◽  
The Cost ◽  
The Impact

SummaryBackgroundVoluntary individual quarantine and voluntary active monitoring of contacts are core disease control strategies for emerging infectious diseases, such as COVID-19. Given the impact of quarantine on resources and individual liberty, it is vital to assess under what conditions individual quarantine can more effectively control COVID-19 than active monitoring. As an epidemic grows, it is also important to consider when these interventions are no longer feasible, and broader mitigation measures must be implemented.MethodsTo estimate the comparative efficacy of these case-based interventions to control COVID-19, we fit a stochastic branching model to reported parameters for the dynamics of the disease. Specifically, we fit to the incubation period distribution and each of two sets of the serial interval distribution: a shorter one with a mean serial interval of 4.8 days and a longer one with a mean of 7.5 days. To assess variable resource settings, we consider two feasibility settings: a high feasibility setting with 90% of contacts traced, a half-day average delay in tracing and symptom recognition, and 90% effective isolation; and low feasibility setting with 50% of contacts traced, a two-day average delay, and 50% effective isolation.FindingsOur results suggest that individual quarantine in high feasibility settings where at least three-quarters of infected contacts are individually quarantined contains an outbreak of COVID-19 with a short serial interval (4.8 days) 84% of the time. However, in settings where this performance is unrealistically high and the outbreak continues to grow, so too will the burden of the number of contacts traced for active monitoring or quarantine. When resources are prioritized for scalable interventions such as social distancing, we show active monitoring or individual quarantine of high-risk contacts can contribute synergistically to mitigation efforts.InterpretationOur model highlights the urgent need for more data on the serial interval and the extent of presymptomatic transmission in order to make data-driven policy decisions regarding the cost-benefit comparisons of individual quarantine vs. active monitoring of contacts. To the extent these interventions can be implemented they can help mitigate the spread of COVID-19.FundingThis work was supported in part by Award Number U54GM088558 from the US National Institute Of General Medical Sciences.

The South America Tomato Leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), Spreads Its Wings in Eastern Africa: Distribution and Socioeconomic Impacts

2019 ◽  
Vol 112 (6) ◽  
pp. 2797-2807 ◽  
Author(s):  
Pascal Osa Aigbedion-Atalor ◽  
Martin P Hill ◽  
Myron P Zalucki ◽  
Francis Obala ◽  
Gamal E Idriss ◽  
...  
Keyword(s):  
Control Strategies ◽  
Sustainable Livelihoods ◽  
Integrated Approach ◽  
Control Measures ◽  
Tuta Absoluta ◽  
Eastern Africa ◽  
Socioeconomic Impacts ◽  
Tomato Production ◽  
The Cost ◽  
The Impact

Abstract Following the arrival of Tuta absoluta Meyrick in the eastern African subregion in 2012, several studies have shown numerous ecological aspects of its invasion. We investigated the impact of T. absoluta on people’s livelihoods across four counties of Kenya. Here, 200 farmers in the country were interviewed in person using semistructured questionnaires. In addition to livelihood surveys, T. absoluta distribution was mapped between 2016 and 2018 to determine its current distribution across four countries (Kenya, Sudan, Tanzania, and Uganda) in the subregion. Albeit a recent invader, T. absoluta is abundant and distributed throughout the subregion and is viewed as the worst invasive alien species of agriculturally sustainable livelihoods by tomato farmers. The arrival of T. absoluta in the subregion has resulted in livelihood losses and increased both the cost of tomato production and frequency of pesticide application. We recommend the implementation of biological control along, with other control measures in an integrated approach, against T. absoluta in the subregion, where its impact on sustainable livelihoods is serious and long-term control strategies are required to curb its detrimental effects.

scholarly journals The economic impact and cost-effectiveness of combined vector-control and dengue vaccination strategies in Thailand: results from a dynamic transmission model

2020 ◽  
Vol 14 (10) ◽  
pp. e0008805
Author(s):  
Gerhart Knerer ◽  
Christine S. M. Currie ◽  
Sally C. Brailsford
Keyword(s):  
Public Health ◽  
Cost Effectiveness ◽  
Vector Control ◽  
Dengue Fever ◽  
Control Strategies ◽  
Cost Effective ◽  
Scenario Analyses ◽  
Life Years ◽  
The Cost ◽  
The Impact

Background and aims Dengue fever is a major public health problem in tropical/subtropical regions. Prior economic analyses have predominantly evaluated either vaccination or vector-control programmes in isolation and do not really consider the incremental benefits and cost-effectiveness of mixed strategies and combination control. We estimated the cost-effectiveness of single and combined approaches in Thailand. Methods The impacts of different control interventions were analysed using a previously published mathematical model of dengue epidemiology and control incorporating seasonality, age structure, consecutive infection, cross protection, immune enhancement and combined vector-host transmission. An economic model was applied to simulation results to estimate the cost-effectiveness of 4 interventions and their various combinations (6 strategies): i) routine vaccination of 1-year olds; ii) chemical vector control strategies targeting adult and larval stages separately; iii) environmental management/ public health education and awareness [EM/ PHEA]). Payer and societal perspectives were considered. The health burden of dengue fever was assessed using disability-adjusted life-years (DALYs) lost. Costs and effects were assessed for 10 years. Costs were discounted at 3% annually and updated to 2013 United States Dollars. Incremental cost-effectiveness analysis was carried out after strategies were rank-ordered by cost, with results presented in a table of incremental analysis. Sensitivity and scenario analyses were undertaken; and the impact and cost-effectiveness of Wolbachia was evaluated in exploratory scenario analyses. Results From the payer and societal perspectives, 2 combination strategies were considered optimal, as all other control strategies were dominated. Vaccination plus adulticide plus EM/ PHEA was deemed cost-effective according to multiple cost-effectiveness criteria. From the societal perspective, incremental differences vs. adulticide and EM/ PHEA resulted in costs of $157.6 million and DALYs lost of 12,599, giving an expected ICER of $12,508 per DALY averted. Exploratory scenario analyses showed Wolbachia to be highly cost-effective ($343 per DALY averted) vs. other single control measures. Conclusions Our model shows that individual interventions can be cost-effective, but that important epidemiological reductions and economic impacts are demonstrated when interventions are combined as part of an integrated approach to combating dengue fever. Exploratory scenario analyses demonstrated the potential epidemiological and cost-effective impact of Wolbachia when deployed at scale on a nationwide basis. Our findings were robust in the face of sensitivity analyses.

Relaxing Synchronization Constraints in Distributed Agent-based Simulations

2013 ◽  
Vol 63 (3) ◽  
Author(s):  
Omar Rihawi ◽  
Yann Secq ◽  
Philippe Mathieu
Keyword(s):  
Time Management ◽  
Large Scale ◽  
Computer Network ◽  
Population Level ◽  
Emergent Properties ◽  
Agent Based ◽  
Multi Agent ◽  
The Cost ◽  
The Impact ◽  
Synchronization Constraints

In the context of situated agents simulations, when the number of agents increases, the number of their interactions will be increased too. These growths leads to higher requirements in memory and computation power. When simulations involve millions of agents, it becomes necessary to distribute the simulator on a computer network. In this paper we study the impact of synchronization policies in such context. Our claim is that when millions of agents are used in a simulation, because observations of these complex systems is made at the population level, emergent properties at the macroscopic level should not be highly impacted if some failure appears at the microscopic level. This paper is focused on the study of the impact of synchronization relaxation in the context of large scale situated agents simulations. We evaluate the cost in performance of several synchronization policies and their impact on the macroscopic properties of simulations. To that aims, we study three different time management mechanisms and evaluate them on two multi-agent applications.

scholarly journals Modeling the impact of threats and vulnerabilities in transport logistics of a developing enterprise

2021 ◽  
pp. 29-36
Author(s):  
Oleg Fedorovich ◽  
Yurii Pronchakov ◽  
Yuliia Leshchenko ◽  
Alina Yelizieva
Keyword(s):  
Optimization Problems ◽  
Cost Minimization ◽  
Mathematical Methods ◽  
Agent Based ◽  
Agent Model ◽  
Event Modeling ◽  
Goods Movement ◽  
The Cost ◽  
Distributed Production ◽  
The Impact

A scientific and appliedproblem of modeling the impact of threats and vulnerabilities in the logistics of transportation of goods of a distributed production system was posed and solved. The relevance of the research topic is associated with the identification of significant threats and the emergence of vulnerabilities, which can lead to deterioration in the main indicators of a developing enterprise. The research solves of the task of increasing of logistic processes effectiveness of goods transportation in a distributed manufacturing system in emerging threats and manifestation of vulnerability conditions. A set of possible threats is analyzed and formed, which influence goods transportation in a heterogeneous transport system of distributed manufacture. A virtual experiment method is proposed for using the experts' opinions regarding the identification of threat factors using a developed multifactorial and multi-response experimental plan, where lines represent the factors and a combination of threat factors, and the columns are associated with possible threats. A manifestation of vulnerabilities risks and emerging threats is used as responses. A regressive dependence to identify the most important threat factors is formed.The cost indicators are used for solving optimization problems, which connected with vulnerability removal, the time of events to vulnerabilities neutralization and risks of threat emergence. The cost minimization associated with the removal (neutralization) of vulnerabilities that may appear when threats emerge. The agent model for simulation and event modeling of a logistic of transportation in a distributed manufacture in conditions of threat factors and vulnerability emergence is proposed. Agent-based modeling allows you to determine the time of goods movement without vulnerability emergence and time of goods movement with vulnerability emergence using possible risk generator. Mathematical methods used systems analysis, the theory of experiments planning, integer (Boolean) programming, agent-based and event modeling.

scholarly journals This time is different: model-based evaluation of the implications of SARS-CoV-2 infection kinetics for disease control

2020 ◽  
Author(s):  
Kaitlyn E Johnson ◽  
Madison Stoddard ◽  
Ryan P Nolan ◽  
Douglas E White ◽  
Natasha Hochberg ◽  
...  
Keyword(s):  
Disease Control ◽  
Control Strategies ◽  
Control Measures ◽  
Testing Strategies ◽  
Health Strategy ◽  
Quantitative Understanding ◽  
Dependent Model ◽  
Primary Basis ◽  
The Impact ◽  
Kinetics Of

As the ongoing COVID-19 pandemic passes from an acute to a chronic situation, countries and territories are grappling with the issue of how to reopen safely. The unique kinetics of infectivity of SARS-CoV-2, with its significant presymptomatic transmission, presents an unprecedented challenge to our intuitions. In this context, a generalizable quantitative understanding of the impact of SARS-CoV-2 infectivity on disease control strategies is vital. We used a previously published time-dependent model of SARS-CoV-2 infectivity (He et al., 2020) to parameterize an epidemiological model of transmission, which was then used to explore the effect of various disease control measures. Our analysis suggests that using symptom-based isolation alone as a control strategy is ineffective in limiting the spread of COVID-19, in contrast to its effectiveness in other diseases, such as SARS and influenza. Additionally, timeliness of testing and tracing strategies to reduce time to isolation, along with widespread adoption of measures to limit transmission are critical for any containment strategy. Our findings suggest that for symptom-based isolation and testing strategies to be effective, reduced transmission is required, reinforcing the importance of measures to limit transmission. From a public health strategy perspective, our findings lend support to the idea that symptomatic isolation should not form the primary basis for COVID-19 disease control.

Assessing the Impact of Temperature Change on the Effectiveness of Insecticide-Treated Nets

2012 ◽  
pp. 241-255
Author(s):  
Gregory J. Davis
Keyword(s):  
Control Strategies ◽  
Global Climate ◽  
Financial Burden ◽  
Insecticide Treated Nets ◽  
Policy Makers ◽  
Agent Based ◽  
Mosquito Abundance ◽  
Vector Borne ◽  
And Control ◽  
The Impact

Malaria is a vector-borne illness affecting millions of lives annually and imposes a heavy financial burden felt worldwide. Moreover, there is growing concern that global climate change, in particular, rising temperature, will increase this burden. As such, policy makers are in need of tools capable of informing them about the potential strengths and weaknesses of intervention and control strategies. A previously developed agent-based model of the Anopheles gambiae mosquito is extended, one of the primary vectors of malaria, to investigate how changes in temperature influence the dynamics of malaria transmission and the effectiveness of a common malaria intervention: insecticide-treated nets (ITNs). Results from the simulations suggest two important findings. Consistent with previous studies, an increase in mosquito abundance as temperature increases is observed. However, the increase in mosquito abundance reduces the effectiveness of ITNs at a given coverage level. The implications and limitations of these findings are discussed.

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