scholarly journals Modeling the Impact of Lock-down on COVID-19 Spread in Malaysia

2020 ◽  
Author(s):  
Altahir A. Altahir ◽  
Nirbhay Mathur ◽  
Loshini Thiruchelvam ◽  
Ghulam E. Mustafa Abro ◽  
Syaimaa’ S. M. Radzi ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Reproduction Number ◽  
Formal Analysis ◽  
Time Frame ◽  
Immature Stage ◽  
Epidemic Spread ◽  
Prevention Measures ◽  
Seir Model ◽  
The World ◽  
The Impact

AbstractAfter a breakdown notified in Wuhan, China in December 2019, COVID-19 is declared as pandemic diseases. To the date more than 13 million confirmed cases and more than half a million are dead around the world. This virus also attached Malaysia in its immature stage where 8718 cases were confirmed and 122 were declared as death. Malaysia responsibly controlled the spread by enforcing MCO. Hence, it is required to visualize the pattern of Covid-19 spread. Also, it is necessary to estimate the impact of the enforced prevention measures. In this paper, an infectious disease dynamic modeling (SEIR) is used to estimate the epidemic spread in Malaysia. The main assumption is to update the reproduction number Rt with respect to the implemented prevention measures. For a time-frame of five month, the Rt was assumed to vary between 2.9 and 0.3. Moreover, the manuscript includes two possible scenarios: the first will be the extension of the stricter measures all over the country, and the second will be the gradual lift of the lock-down. After implementing several stages of lock-down we have found that the estimated values of the Rt with respect to the strictness degree varies between 0.2 to 1.1. A continuous strict lock-down may reduce the Rt to 0.2 and accordingly the estimated active cases will be reduced to 20 by the beginning of September 2020. In contrast, the second scenario considers a gradual lift of the enforced prevention measures by the end of June 2020, here we have considered three possible outcomes according to the MCO relaxation. Thus, the estimated values of Rt = 0.7, 0.9, 1.1, which shows a rapid increase in the number of active cases. The implemented SEIR model shows a close resemblance with the actual data recorded from 10, March till 7, July 2020.Author summaryConceptualization, A.A.A; methodology, A.A.A, N.M; validation, A.A.A, N.M; formal analysis, A.A.A; investigation, N.M, A.A.A; resources, G.E.M.A, L.T; data collection, L.T, N.M; writing—original draft preparation, A.A.A, L.T, G.E.M.A, N.M; writing—review and editing, V.S.A, S.C.D, B.S.G, P.S, S.A.B.M.Z, N.M; visualization, N.M; supervision, V.S.A; project administration, V.S.A. All authors have read and agreed to the published version of the manuscript

scholarly journals Will International Rules on Subsidies Disrupt the World Trading System?

2006 ◽  
Vol 96 (3) ◽  
pp. 877-895 ◽  
Author(s):  
Kyle Bagwell ◽  
Robert W Staiger
Keyword(s):  
Market Access ◽  
Formal Analysis ◽  
Trading System ◽  
Domestic Production ◽  
Multilateral Trading System ◽  
The World ◽  
World Trading System ◽  
The Creation ◽  
The Impact ◽  
The Multilateral Trading System

We provide a first formal analysis of the international rules that govern the use of subsidies to domestic production. Our analysis highlights the impact of the new subsidy disciplines that were added to GATT rules with the creation of the WTO. While GATT subsidy rules were typically viewed as weak and inadequate, our results suggest that the key changes introduced by the WTO subsidy rules may ultimately do more harm than good to the multilateral trading system by undermining the ability of tariff negotiations to serve as the mechanism for expanding market access to more efficient levels.

scholarly journals Do Democratic Economies Grow Faster? The Case of Asia vs. the EU

2018 ◽  
Vol 14 (2) ◽  
pp. 115
Author(s):  
Samuel D. Barrows
Keyword(s):  
World Bank ◽  
Capita Income ◽  
Time Frame ◽  
Per Capita Income ◽  
The World Bank ◽  
The World ◽  
Per Capita ◽  
Economic Growth Rates ◽  
The Impact ◽  
The Eu

The dynamics of the five fastest growing GDP per capita economies in Asia and the EU are studied between 2010 and 2014. This time frame was selected in order to avoid the height of the 2008-2009 financial crisis, but to include the stimulus and recovery periods which occurred afterward. The intent was not to compare the recoveries or the impact of the stimulus programs. The intent was to compare the economic growth rates of the two groups and also the absolute per capita income along with five topic areas on economies including: configuration, utilization, investments, demographics, and outcomes. A total of twenty measurements are used for assessment from the World Bank databank website. The findings are that the Asian economies grew faster while the EU economies had a higher per capita income. The workforces of the Asia economies are also younger and more flexible whereas the workforces of the EU economies are older, but more educated. Discussions include the links between effective governments and economic development and the links between democracy and economic levels.

scholarly journals Threshold parameters for a model of epidemic spread among households and workplaces

2009 ◽  
Vol 6 (40) ◽  
pp. 979-987 ◽  
Author(s):  
L. Pellis ◽  
N. M. Ferguson ◽  
C. Fraser
Keyword(s):  
Infectious Disease ◽  
Basic Reproduction Number ◽  
Reproduction Number ◽  
Model Parameters ◽  
Epidemic Spread ◽  
Threshold Parameter ◽  
Disease Epidemiology ◽  
Infectious Disease Epidemiology ◽  
Complex Models ◽  
The Basic Reproduction Number

The basic reproduction number R 0 is one of the most important concepts in modern infectious disease epidemiology. However, for more realistic and more complex models than those assuming homogeneous mixing in the population, other threshold quantities can be defined that are sometimes more useful and easily derived in terms of model parameters. In this paper, we present a model for the spread of a permanently immunizing infection in a population socially structured into households and workplaces/schools, and we propose and discuss a new household-to-household reproduction number R H for it. We show how R H overcomes some of the limitations of a previously proposed threshold parameter, and we highlight its relationship with the effort required to control an epidemic when interventions are targeted at randomly selected households.

scholarly journals Optimal control of COVID-19

2021 ◽  
Vol 11 (1) ◽  
pp. 114-122
Author(s):  
Nacima Moussouni ◽  
Mohamed Aliane
Keyword(s):  
Infectious Disease ◽  
Optimal Control ◽  
Maximum Principle ◽  
Indirect Method ◽  
Shooting Method ◽  
Discretization Method ◽  
Seir Model ◽  
The World ◽  
Respiratory Droplets ◽  
The Pontryagin Maximum Principle

Coronavirus disease of 2019 or COVID-19 (acronym for coronavirus disease 2019) is an emerging infectious disease caused by a strain of coronavirus called SARS-CoV-22, contagious with human-to-human transmission via respiratory droplets or by touching contaminated surfaces then touching them face. Faced with what the world lives, to define this problem, we have modeled it as an optimal control problem based on the models of William Ogilvy Kermack et Anderson Gray McKendrick, called SEIR model, modified by adding compartments suitable for our study. Our objective in this work is to maximize the number of recovered people while minimizing the number of infected. We solved the problem theoretically using the Pontryagin maximum principle, numerically we used and compared results of two methods namely the indirect method (shooting method) and the Euler discretization method, implemented in MATLAB.

scholarly journals Analysis of Effectiveness of Quarantine Measures in Controlling COVID-19

2020 ◽  
Author(s):  
Garima Kaushik ◽  
Shaney Mantri ◽  
Shrishti Kaushik ◽  
Dhananjay Kalbande ◽  
B. N. Chaudhari
Keyword(s):  
Preventive Measures ◽  
Deterministic Model ◽  
Reproduction Number ◽  
Intervention Strategies ◽  
Control Measures ◽  
Transmission Rates ◽  
The People ◽  
The World ◽  
The Impact ◽  
Insight Into

AbstractCOVID-19 has created an interesting discourse among the people of the world particularly regarding preventive measures of infectious diseases. In this paper, the authors forecast the spread of the Coronavirus outbreak and study how the reduction of transmission rates influences its decline. The paper makes use of the SIR (Susceptible Infected Recovered) Model which is a deterministic model used in the field of epidemiology-based on differential equations derived from sections of the population. The Basic Reproduction Number (Ro) represents the criticality of the epidemic in numeric terms. Forecasting an epidemic provides insights about the geographic spreading of the disease and the case incidences required to better inform intervention strategists about situations that may occur during the outbreak. Through this research paper, the authors wish to provide an insight into the impact of control measures on the pandemic. By drawing a comparison of three countries and their quarantine measures, observations on the decline of the outbreak are made. Authors intend to guide the intervention strategies of under-resourced countries like India and aid in the overall containment of the outbreak.

scholarly journals An SEIR Model with Contact Tracing and Age-Structured Social Mixing for COVID-19 outbreak

2020 ◽  
Author(s):  
Ali Teimouri
Keyword(s):  
Reproduction Number ◽  
Contact Tracing ◽  
Seir Model ◽  
Expectation Value ◽  
Proposed Model ◽  
Social Mixing ◽  
The World ◽  
Age Structured ◽  
And Control ◽  
Explicit Relation

AbstractIn December 2019 a severe acute respiratory syndrome now known as SARS-CoV-2 began to surge in Wuhan, China. The virus soon spread throughout the world to become a pandemic. Since the outbreak various measures were put in place to contain and control the spread, these interventions were mostly based on compartmental models in epidemiology with the main goal of controlling and monitoring the rate of the basic and effective reproduction number. In this paper, we propose an SEIR model where we incorporate contact tracing and age-structured social mixing. We show the explicit relation between contact tracing and social mixing and other relevant parameters of the proposed model. We derive a formula for the effective reproduction number which is expressed in terms of reported cases, tracing quantities and social mixing. We use this formula to determine the expectation value of the effective reproduction number in London, UK.

scholarly journals Accounting for super-spreading gives the basic reproduction number R0 of COVID-19 that is higher than initially estimated

2020 ◽  
Author(s):  
Marek Kochańczyk ◽  
Frederic Grabowski ◽  
Tomasz Lipniacki
Keyword(s):  
Basic Reproduction Number ◽  
Doubling Time ◽  
Reproduction Number ◽  
Case Reports ◽  
Individual Case ◽  
Epidemic Spread ◽  
Empirical Estimation ◽  
Seir Model ◽  
Initial Stage ◽  
The Basic Reproduction Number

Transmission of infectious diseases is characterized by the basic reproduction number R0, a metric used to assess the threat posed by an outbreak and inform proportionate preventive decision-making. Based on individual case reports from the initial stage of the coronavirus disease 2019 epidemic, R0 is often estimated to range between 2 and 4. In this report, we show that a SEIR model that properly accounts for the distribution of the incubation period suggests that R0 lie in the range 4.4–11.7. This estimate is based on the doubling time observed in the near-exponential phases of the epidemic spread in China, United States, and six European countries. To support our empirical estimation, we analyze stochastic trajectories of the SEIR model showing that in the presence of super-spreaders the calculations based on individual cases reported during the initial phase of the outbreak systematically overestimate the doubling time and thus underestimate the actual value of R0.

scholarly journals Dynamics Analysis of an Epidemiological Model with Media Impact and Two Delays

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Lianwen Wang ◽  
Yong Li ◽  
Liuyong Pang
Keyword(s):  
Reproduction Number ◽  
Threshold Dynamics ◽  
Global Dynamics ◽  
Lyapunov Functionals ◽  
Dynamics Analysis ◽  
Epidemic Spread ◽  
Media Impact ◽  
Timely Response ◽  
Two Delays ◽  
The Impact

This paper is concerned with exploring the global dynamics of SEIR epidemic model with media impact, which incorporates latency and relapse delays. The permanence of the model is carefully discussed. By suitable Lyapunov functionals, we establish the global stability of the equilibria. It is found that the basic reproduction number completely determines the threshold dynamics of the SEIR model. Finally, the impact of media on the epidemic spread is studied, which reveals that timely response of media and individuals may play a more key role in disease control.

scholarly journals Health Sufficiency Indicators for Pandemic Monitoring

2021 ◽  
Vol 18 (10) ◽  
pp. 5358
Author(s):  
Javier M. Moguerza ◽  
Salvador Perelló Oliver ◽  
Isaac Martín de Diego ◽  
Víctor Aceña ◽  
Carmen Lancho ◽  
...  
Keyword(s):  
Health Care ◽  
Health System ◽  
Health Systems ◽  
Basic Information ◽  
Prevention Measures ◽  
Early Prevention ◽  
The World ◽  
Disease Spreading ◽  
The Impact ◽  
Spanish Health

The outbreak of the COVID-19 disease, spreading all around the world and causing a worldwide pandemic, has lead to the collapse of the health systems of the most affected countries. Due to the ease of transmission, early prevention measures are proved to be fundamental to control the pandemic and, hence, the saturation of the health systems. Given the difficulty of obtaining characteristics of these systems of different countries and regions, it is necessary to define indicators based on basic information that enable the assessment of the evolution of the impact of a disease in a health system along with fair comparisons among different ones. This present paper introduces the Health Sufficiency Indicator (HSI), in its accumulated and daily versions. This indicator measures the additional pressure that a health care system has to deal with due to a pandemic. Hence, it allows to evaluate the capacity of a health system to give response to the corresponding needs arising from a pandemic and to compare the evolution of the disease among different regions. In addition, the Potential Occupancy Ratio (POR) in both its hospital ward bed and ICU bed versions is here introduced to asses the impact of the pandemic in the capacity of hospitals. These indicators and other well-known ones are applied to track the evolution of the impact of the disease on the Spanish health system during the first wave of the pandemic, both on national and regional levels. An international comparison among the most affected countries is also performed.

scholarly journals Determination of critical decision points for COVID-19 measures in Japan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Junu Kim ◽  
Kensaku Matsunami ◽  
Kozue Okamura ◽  
Sara Badr ◽  
Hirokazu Sugiyama
Keyword(s):  
Time Delay ◽  
Infection Rate ◽  
Reproduction Number ◽  
Sir Model ◽  
Infection Rates ◽  
Seir Model ◽  
Decision Points ◽  
Medical Institutions ◽  
The World

AbstractCoronavirus disease 2019 (COVID-19) has spread throughout the world. The prediction of the number of cases has become essential to governments’ ability to define policies and take countermeasures in advance. The numbers of cases have been estimated using compartment models of infectious diseases such as the susceptible-infected-removed (SIR) model and its derived models. However, the required use of hypothetical future values for parameters, such as the effective reproduction number or infection rate, increases the uncertainty of the prediction results. Here, we describe our model for forecasting future COVID-19 cases based on observed data by considering the time delay (tdelay). We used machine learning to estimate the future infection rate based on real-time mobility, temperature, and relative humidity. We then used this calculation with the susceptible-exposed-infectious-removed (SEIR) model to forecast future cases with less uncertainty. The results suggest that changes in mobility affect observed infection rates with 5–10 days of time delay. This window should be accounted for in the decision-making phase especially during periods with predicted infection surges. Our prediction model helps governments and medical institutions to take targeted early countermeasures at critical decision points regarding mobility to avoid significant levels of infection rise.

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