scholarly journals Can medication mitigate the need for a strict lock down?: A mathematical study of control strategies for COVID-19 infection

2020 ◽  
Author(s):  
Mohsin Ali ◽  
Mudassar Imran ◽  
Adnan Khan
Keyword(s):  
Reproduction Number ◽  
Virus Disease ◽  
Control Strategies ◽  
Effective Control ◽  
Control Mechanisms ◽  
Mathematical Study ◽  
Epidemic Curve ◽  
The World ◽  
Asymptomatic Individuals ◽  
Pharmaceutical Interventions

Abstract BackgroundCOVID-19 is a pandemic that has swept across the world in 2020. To date the only effective control mechanisms were non-pharmaceutical interventions, however there have been encouraging reports regarding possible medication in the literature, with emergency approval given to some drugs in various countries.MethodsWe formulate a deterministic epidemic model to study the effects of medication on the transmission dynamics of Corona Virus Disease (COVID-19). We are especially interested in how the availability of medication could change the necessary quarantine measures for effective control of the disease. We model the transmission by extending the SEIR model to include asymptomatic, quarantined, isolated and medicated population compartments.ResultsWe calculate the basic reproduction number R0 and show that for R0<1 the disease dies out and for R0>1 the disease is endemic. Using sensitivity analysis we establish that R0 is most sensitive to the rates of quarantine and medication. We also study how the effectiveness and the rate of medication along with the quarantine rate affect R0. We devise optimal quarantine, medication and isolation strategies, noting that availability of medication reduces the duration and severity of the lock-down needed for effective disease control.ConclusionOur study also reinforces the idea that with the availability of medication, while the severity of the lock downs can be eased over time some social distancing protocols need to be observed, at least till a vaccine is found. We also analyze the COVID-19 outbreak data for four different countries, in two of these, India and Pakistan the curve is still rising, and in he other two, Italy and Spain, the epidemic curve is now falling due to effective quarantine measures. We provide estimates of R0 and the proportion of asymptomatic individuals in the population for these countries.

scholarly journals Can medication mitigate the need for a strict lock down?: A mathematical study of control strategies for COVID-19 infection

2020 ◽  
Author(s):  
Mohsin Ali ◽  
Mudassar Imran ◽  
Adnan Khan
Keyword(s):  
Reproduction Number ◽  
Virus Disease ◽  
Control Strategies ◽  
Transmission Dynamics ◽  
Effective Control ◽  
Mathematical Study ◽  
Seir Model ◽  
Epidemic Curve ◽  
Asymptomatic Individuals ◽  
Over Time

AbstractWe formulate a deterministic epidemic model to study the effects of medication on the transmission dynamics of Corona Virus Disease (COVID-19). We are especially interested in how the availability of medication could change the necessary quarantine measures for effective control of the disease. We model the transmission by extending the SEIR model to include asymptomatic, quarantined, isolated and medicated population compartments. We calculate the basic reproduction number R0 and show that for R0 < 1 the disease dies out and for R0 > 1 the disease is endemic. Using sensitivity analysis we establish that R0 is most sensitive to the rates of quarantine and medication. We also study how the effectiveness and the rate of medication along with the quarantine rate affect R0. We devise optimal quarantine, medication and isolation strategies, noting that availability of medication reduces the duration and severity of the lock-down needed for effective disease control. Our study also reinforces the idea that with the availability of medication, while the severity of the lock downs can be eased over time some social distancing protocols need to be observed, at least till a vaccine is found. We also analyze the COVID-109 outbreak data for four different countries, in two of these, India and Pakistan the curve is still rising, and in he other two, Italy and Spain, the epidemic curve is now falling due to effective quarantine measures. We provide estimates of R0 and the proportion of asymptomatic individuals in the population for these countries.

scholarly journals Mitigating the transmission of infection and death due to SARS-CoV-2 through non-pharmaceutical interventions and repurposing drugs

2020 ◽  
Author(s):  
Chittaranjan Mondal ◽  
Debadatta Adak ◽  
Abhijit Majumder ◽  
Nandadulal Bairagi
Keyword(s):  
Reproduction Number ◽  
Control Strategies ◽  
Intervention Strategies ◽  
Personal Hygiene ◽  
Virus Spread ◽  
Combined Use ◽  
The Right ◽  
And Control ◽  
Pharmaceutical Interventions

The Covid-19 pandemic has put the world under immeasurable stress. There is no specific drug or vaccine that can cure the infection or protect people from the infection of coronavirus. It is therefore prudent to use the existing resources and control strategies in an optimal way to contain the virus spread and provide the best possible treatments to the infected individuals. Use of the repurposing drugs along with the non-pharmaceutical intervention strategies may be the right way for fighting against the ongoing pandemic. It is the objective of this work to demonstrate through mathematical modelling and analysis how and to what extent such control strategies can improve the overall Covid-19 epidemic burden. The criteria for disease elimination & persistence were established through the basic reproduction number. A case study with the Indian Covid-19 epidemic data is presented to visualize and illustrate the effects of lockdown, maintaining personal hygiene & safe distancing, and repurposing drugs. It is shown that India can significantly improve the overall Covid-19 epidemic burden through the combined use of NPIs and repurposing drugs though containment of spreading is difficult without serious community participation.

scholarly journals Evaluating the trade-off between transmissibility and virulence of SARS-CoV-2 by mathematical modeling

2021 ◽  
Author(s):  
Hyun Mo Yang ◽  
Luis Pedro Lombardi Junior ◽  
Ariana Campos Yang
Keyword(s):  
Mathematical Model ◽  
Reproduction Number ◽  
Sao Paulo ◽  
Model Parameters ◽  
São Paulo ◽  
Paulo State ◽  
The World ◽  
Age Dependent ◽  
São Paulo State ◽  
Asymptomatic Individuals

AbstractBackgroundAt the beginning of 2020, SARS-CoV-2 spread to all continents, and since then, mutations have appeared in different regions of the world. The appearance of more virulent mutations leads to asseverate that they are also more transmissible. We analyzed the lower and higher virulent SARS-CoV-2 epidemics to establish a relationship between transmissibility and virulence based on a mathematical model.MethodsA compartmental mathematical model based on the CoViD-19 natural history encompassing the age-dependent fatality was applied to evaluate the SARS-CoV-2 transmissibility and virulence. The transmissibility was measured by the basic reproduction number R0 and the virulence by the proportion of asymptomatic individuals. The model parameters were fitted considering the observed data from São Paulo State.ResultsThe numbers of severe CoViD-19 and deaths are three times higher, but R0 is 25% lower in more virulent SARS-CoV-2 transmission than in a less virulent one. However, the number of more virulent SARS-CoV-2 transmitting individuals is 25% lower, mainly due to symptomatic individuals’ isolation, explaining the increased transmission in lower virulence.ConclusionsThe quarantine study in São Paulo State showed that the more virulent SARS-CoV-2 resulted in a higher number of fatalities but less transmissible than the less virulent one. One possible explanation for the number of deaths surpassing that predicted by the low virulent SARS-CoV-2 infection could be the transmission of more virulent variant(s).

scholarly journals Ventilator-associated pneumonia among ICU patients in WHO Southeast Asian region: A systematic review

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247832
Author(s):  
Sanjeev Kharel ◽  
Anil Bist ◽  
Shyam Kumar Mishra
Keyword(s):  
Antibiotic Resistance ◽  
Control Strategies ◽  
Health Resources ◽  
Cost Effective ◽  
Effective Control ◽  
Ventilator Associated Pneumonia ◽  
Asian Region ◽  
The World ◽  
Limited Health ◽  
Gram Negative Organisms

Ventilator-associated pneumonia (VAP) is one of the most frequent ICU-acquired infections and a leading cause of death among patients in Intensive Care Unit (ICU). The South East Asian Region is a part of the world with limited health resources where infectious diseases are still underestimated. We aimed to review the literature in this part of the world to describe incidence, mortality and microbiological evidence of VAP and explore preventive and control strategies. We selected 24 peer-reviewed articles published from January 1, 2000 to September 1, 2020 from electronic databases and manual searching for observational studies among adult patients diagnosed with VAP expressed per thousand days admitted in ICU. The VAP rates ranged from 2.13 to 116 per thousand days, varying among different countries of this region. A significant rate of mortality was observed in 13 studies ranging from 16.2% to 74.1%. Gram negative organisms like Acinetobacter spp., Pseudomonas aeruginosa and Klebsiella pneumoniae and Gram-positive organisms like Staphylococcus aureus and Enterococcus species were frequently found. Our findings suggest an alarming situation of VAP among patients of most of the countries of this region with increasing incidence, mortality and antibiotic resistance. Thus, there is an urgent need for cost effective control and preventive measures like interventional studies and educational programs on staff training, hand hygiene, awareness on antibiotic resistance, implementation of antibiotic stewardship programs and appropriate use of ventilator bundle approach.

MATHEMATICAL STUDY OF THE IMPACT OF QUARANTINE, ISOLATION AND VACCINATION IN CURTAILING AN EPIDEMIC

2007 ◽  
Vol 15 (02) ◽  
pp. 185-202 ◽  
Author(s):  
CHANDRA N. PODDER ◽  
ABBA B. GUMEL ◽  
CHRIS S. BOWMAN ◽  
ROBERT G. MCLEOD
Keyword(s):  
Disease Burden ◽  
Compartmental Model ◽  
Reproduction Number ◽  
Control Measures ◽  
Vaccination Program ◽  
Reproductive Number ◽  
Mathematical Study ◽  
Asymptomatic Individuals ◽  
Combined Impact ◽  
The Impact

The quarantine of suspected cases and isolation of individuals with symptoms are two of the primary public health control measures for combating the spread of a communicable emerging or re-emerging disease. Implementing these measures, however, can inflict significant socio-economic and psychological costs. This paper presents a deterministic compartmental model for assessing the single and combined impact of quarantine and isolation to contain an epidemic. Comparisons are made with a mass vaccination program. The model is simulated using parameters for influenza-type diseases such as SARS. The study shows that even for an epidemic in which asymptomatic transmission does not occur, the quarantine of asymptomatically-infected individuals can be more effective than only isolating individuals with symptoms, if the associated reproductive number is high enough. For the case where asymptomatic transmission occurs, it is shown that isolation is more effective for a disease with a small basic reproduction number and transmission coefficient of asymptomatically-infected individuals. If asymptomatic individuals transmit at a rate that is at least 20% that of symptomatic individuals, quarantine is always more effective. The study further shows that the reduction in disease burden obtained from a combined quarantine and isolation program can be comparable to that obtained by a vaccination program, if the former is implemented quickly enough after the onset of the outbreak. If the implementation of such a quarantine/isolation program is delayed, however, even for a short while, its effectiveness decreases rapidly.

scholarly journals Control Strategies to Curtail Transmission of COVID-19

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Nita H. Shah ◽  
Ankush H. Suthar ◽  
Ekta N. Jayswal
Keyword(s):  
Optimal Control Theory ◽  
Reproduction Number ◽  
Control Strategies ◽  
Intervention Strategies ◽  
Public Health Emergency ◽  
Transmission Dynamics ◽  
World Health ◽  
The World ◽  
Health Organization ◽  
The Impact

On 11 March 2020, the World Health Organization declared the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) a pandemic and a Public Health Emergency of International Concern. As of 29 March 2020, coronavirus disease 2019 (COVID-19) has affected 199 countries and territories, resulting in 683,536 positive cases and causing 32,139 deaths. The pandemic has the potential to become extremely destructive globally if not treated seriously. In this study, we propose a generalized SEIR model of COVID-19 to study the behaviour of its transmission under different control strategies. In the model, all possible cases of human-to-human transmission are considered and its reproduction number is formulated to analyse the accurate transmission dynamics of the coronavirus outbreak. Optimal control theory is applied to the model to demonstrate the impact of various intervention strategies, including voluntary quarantine, isolation of infected individuals, improving an individual's immunity, and hospitalization. In addition, the effect of control strategies on the model is analysed graphically by simulating the model numerically.

scholarly journals Modeling Mayaro and Chikungunya Control Strategies in Rio de Janeiro Outbreaks

2019 ◽  
Author(s):  
Esteban Dodero-Rojas ◽  
Luiza G. Ferreira ◽  
Vitor B. P. Leite ◽  
José N. Onuchic ◽  
Vinícius G. Contessoto
Keyword(s):  
Rio De Janeiro ◽  
Reproduction Number ◽  
Control Strategies ◽  
Health Surveillance ◽  
Epidemic Outbreak ◽  
Infected People ◽  
The World ◽  
Mayaro Virus ◽  
The City ◽  
Significant Health

AbstractMosquito-borne diseases have become a significant health issue in many regions around the world. For tropical countries, diseases such as Dengue, Zika, and Chikungunya, became epidemic in the last decades. Health surveillance reports during this period were crucial in providing scientific-based information to guide decision making and resources allocation to control outbreaks. In this work, we perform data analysis of last Chikungunya epidemics in the city of Rio de Janeiro by applying a compartmental mathematical model. We estimate the “basic reproduction number” for those outbreaks and predict the potential epidemic outbreak of Mayaro virus. We also simulated several scenarios with different public interventions to decrease the number of infected people. Such scenarios should provide insights about possible strategies to control future outbreaks.

scholarly journals COVID-19 in the Eyes of Community Leaders in Selected Rural Districts in Eastern Uganda

2021 ◽  
pp. 20-37
Author(s):  
Abdul Walusansa ◽  
Jacob S. Iramiot ◽  
Joseph L. Mpagi ◽  
Ali Kudamba ◽  
Shaban A. Okurut ◽  
...  
Keyword(s):  
Virus Disease ◽  
Control Measures ◽  
World Health ◽  
Community Leaders ◽  
Effective Control ◽  
Convenience Sample ◽  
Rural Settings ◽  
The World ◽  
Knowledge Levels ◽  
Eastern Uganda

Introduction: Corona virus disease (COVID-19) is one of the topmost global hindrances to human existence. Rural settings have been reported to be more vulnerable in some parts of the world. In Uganda, community leaders in rural villages are among the immediate personnel mandated to support compliance with preventive guidelines, and to identify and report/deliver COVID-19 cases to health units. We examined the potential risks of COVID-19 transmission, knowledge levels, perceptions and opinions of Village Council Leaders (VCLs) in selected districts in Eastern Uganda, to support the design of risk-based COVID-19 control measures in rural settings, to protect lives better. Methodology: A convenience sample of ten VLCs were purposively selected in three districts in Eastern Uganda. Pretested questionnaires and in-depth interviews were used to assess the knowledge levels, perceptions, and opinions of respondents about COVID-19. An observational survey was also conducted to examine the barriers to effective control of COVID-19, with reference to health guidelines set by the Ugandan government and the World Health Organization. Data was analyzed using HyperRESEARCH 2.8 software, and STATA version-15.0. Results: Eighty percent of VCLs reported that they were formally engaged in the fight against COVID-19, and the common means of engagement were; dissemination of COVID-19 information by word of mouth, regulation of public events, and monitoring of visitors that come from distant places. All clients reported having received some information about this pandemic, but there was generally low knowledge on some vital aspects: 70% of the respondents did not know the meaning of COVID-19; 100% were uninformed on these common symptoms; headache, sore throat, nausea, and loss of taste & smell; 10% did not know if willingness to conform to health guidelines may affect COVID-19 prevention, and they believed that domestic animals are viable vectors. Radio was the commonest source of COVID-19 information, but it was confounded by poor quality of radio-signals. Most respondents were of the view that in the communities they lead; inaccessibility to authentic health information, financial constraints, and belief that COVID-19 is a fallacy, were some of the leading obstacles to the fight against the pandemic. Low awareness and misconceptions on COVID-19 could be explained by; technological challenges, low literacy levels, and dissemination of wrong information about this pandemic. From the observational survey, the major factors which might intensify the risk of COVID-19 spread were: scarcity of requirements for hand hygiene, face protection, violation of health guidelines and directives, porous borders, terrain, and use of potentially polluted open water sources. Conclusion: Communities in Eastern Uganda are vulnerable to the drastic spread of COVID-19 due to challenges related to: low awareness, poor compliance with preventive guidelines, finances, technology, terrain, illiteracy, scarcity of protective wear and hygiene resources. Awareness creation, material aid, execution of preventive rules, and more research on COVID-19 are warranted.

scholarly journals Cost effective reproduction number based strategies for reducing deaths from COVID-19

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christopher Thron ◽  
Vianney Mbazumutima ◽  
Luis V. Tamayo ◽  
Léonard Todjihounde
Keyword(s):  
High Risk ◽  
Reproduction Number ◽  
Control Strategies ◽  
Cost Model ◽  
Cost Effective ◽  
Control Measures ◽  
Effective Control ◽  
Target Value ◽  
Heuristic Strategies ◽  
Implementation Costs

AbstractIn epidemiology, the effective reproduction number $R_{e}$ R e is used to characterize the growth rate of an epidemic outbreak. If $R_{e} >1$ R e > 1 , the epidemic worsens, and if $R_{e}< 1$ R e < 1 , then it subsides and eventually dies out. In this paper, we investigate properties of $R_{e}$ R e for a modified SEIR model of COVID-19 in the city of Houston, TX USA, in which the population is divided into low-risk and high-risk subpopulations. The response of $R_{e}$ R e to two types of control measures (testing and distancing) applied to the two different subpopulations is characterized. A nonlinear cost model is used for control measures, to include the effects of diminishing returns. Lowest-cost control combinations for reducing instantaneous $R_{e}$ R e to a given value are computed. We propose three types of heuristic strategies for mitigating COVID-19 that are targeted at reducing $R_{e}$ R e , and we exhibit the tradeoffs between strategy implementation costs and number of deaths. We also consider two variants of each type of strategy: basic strategies, which consider only the effects of controls on $R_{e}$ R e , without regard to subpopulation; and high-risk prioritizing strategies, which maximize control of the high-risk subpopulation. Results showed that of the three heuristic strategy types, the most cost-effective involved setting a target value for $R_{e}$ R e and applying sufficient controls to attain that target value. This heuristic led to strategies that begin with strict distancing of the entire population, later followed by increased testing. Strategies that maximize control on high-risk individuals were less cost-effective than basic strategies that emphasize reduction of the rate of spreading of the disease. The model shows that delaying the start of control measures past a certain point greatly worsens strategy outcomes. We conclude that the effective reproduction can be a valuable real-time indicator in determining cost-effective control strategies.

scholarly journals Inter-provincial disparity of COVID-19 transmission and control in Nepal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Buddhi Pantha ◽  
Subas Acharya ◽  
Hem Raj Joshi ◽  
Naveen K. Vaidya
Keyword(s):  
Growth Rate ◽  
Disease Transmission ◽  
Reproduction Number ◽  
Control Strategies ◽  
National Level ◽  
Effective Control ◽  
Data Set ◽  
Control Policies ◽  
Local Spread ◽  
And Control

AbstractDespite the global efforts to mitigate the ongoing COVID-19 pandemic, the disease transmission and the effective controls still remain uncertain as the outcome of the epidemic varies from place to place. In this regard, the province-wise data from Nepal provides a unique opportunity to study the effective control strategies. This is because (a) some provinces of Nepal share an open-border with India, resulting in a significantly high inflow of COVID-19 cases from India; (b) despite the inflow of a considerable number of cases, the local spread was quite controlled until mid-June of 2020, presumably due to control policies implemented; and (c) the relaxation of policies caused a rapid surge of the COVID-19 cases, providing a multi-phasic trend of disease dynamics. In this study, we used this unique data set to explore the inter-provincial disparities of the important indicators, such as epidemic trend, epidemic growth rate, and reproduction numbers. Furthermore, we extended our analysis to identify prevention and control policies that are effective in altering these indicators. Our analysis identified a noticeable inter-province variation in the epidemic trend (3 per day to 104 per day linear increase during third surge period), the median daily growth rate (1 to 4% per day exponential growth), the basic reproduction number (0.71 to 1.21), and the effective reproduction number (maximum values ranging from 1.20 to 2.86). Importantly, results from our modeling show that the type and number of control strategies that are effective in altering the indicators vary among provinces, underscoring the need for province-focused strategies along with the national-level strategy in order to ensure the control of a local spread.

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