Corpus overview


Overview

MeSH Disease

Human Phenotype

Falls (2)


Transmission

Seroprevalence
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    Societal heterogeneity contributes to complex dynamic patterns of the COVID-19 pandemics: insights from a novel Stochastic Heterogeneous Epidemic Model ( SHEM MESHD)

    Authors: Alexander V Maltsev; Michael Stern

    doi:10.1101/2020.07.10.20150813 Date: 2020-07-11 Source: medRxiv

    After months of COVID-19 quarantine, businesses are reopening their doors and people are reentering society. Within the current COVID-19 data, after a slow-down of infection MESHD, a new peak in active cases is already forming. Here we developed a new Stochastic Heterogeneous Epidemic Model (SHEM) to investigate genesis of complex pandemic patterns with the focus on the role of heterogenous societal structure. Using this model with R0 TRANS of COVID-19, we simulated viral infection MESHD in different scenarios where isolated, communities surround the main cluster of the population. Depending on the parameters of heterogeneity and isolation period, our simulations generated a multimodal growth periods with multiple peaks, an extended plateau, a prolonged tail, or a delayed second wave of infection MESHD. We show that timing and magnitude of infection for previously unaffected isolated clusters of people, such as suburban neighborhoods, are critical aspects of these patterns. Our model can be applied to communities at any given scale of population described as a fractal-like structure, i.e. from the entire human population, to a country, down to a province or city levels with relevant societal heterogeneity structure. The current COVID-19 pandemic development worldwide and in the US follows a bimodal rise pattern, qualitatively similar to that in our simulations. We interpret our data to indicate that the secondary peak in the pattern is contributed by the states and counties in the US with late infection MESHD surges that are analogous to isolated suburbs in our model. Furthermore, the on-going early reopening, i.e. premature partial reopening in our model, is further accelerating the peak rise. This peak now reaches new heights, forcing many states in the US to reverse their policies and reestablish their quarantine measures. Our results support these timely and effective measures: we show that longer quarantine periods can reduce the number of deaths MESHD and transform the current trend into a substantially delayed (>1 year) second wave. If this scenario becomes a reality, it is important (i) to develop the vaccine and/or effective treatment before the second wave; (ii) to warn people living in suburbs that it is these isolated areas that may hold a false sense of security, but they should continue to take extra care for their public health.

    Study of the Dependence of Effective Reproduction Number TRANS of COVID-19 on the Temperature and Humidity: A Case Study with the Indian States

    Authors: Manoj Mandal; Subhradeep Patra; Sabyasachi Pal; Suman Acharya; Mangal Hazra

    doi:10.1101/2020.07.05.20146324 Date: 2020-07-06 Source: medRxiv

    Corona Virus Disease MESHD 2019 (COVID-19) started in Wuhan province of China in November 2019 and within a short time, it was declared as a worldwide pandemic by World Health Organisation due to very fast worldwide spread of the virus. In the absence of any vaccine, various mitigation measures were used. In the past, the effect of temperature and humidity on the spread of the virus was studied for a very early phase of the data with mixed results. We are studying the impact of COVID-19 on the maximum temperature and relative humidity of a place using Indian states as test cases for SIR, SIRD, and SEIR models. We used a linear regression method to look for any dependency between effective reproduction number TRANS with maximum temperature and relative humidity. Most of the states show a correlation with the negative slope between the effective reproduction number TRANS with the maximum temperature and the relative humidity. It indicates that the effective reproduction number TRANS goes down as maximum temperature or relative humidity rise. But, the regression coefficient R2 is low for these correlations which means that the correlation is not strong.

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

    Authors: Mohsin Ali; Mudassar Imran; Adnan Khan

    doi:10.21203/rs.3.rs-35440/v1 Date: 2020-06-14 Source: ResearchSquare

    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 TRANS dynamics of Corona Virus Disease MESHD (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 TRANS by extending the SEIR model to include asymptomatic TRANS, quarantined, isolated and medicated population compartments.ResultsWe calculate the basic reproduction number TRANS R0 TRANS and show that for R0 TRANS<1 the disease dies out and for R0 TRANS>1 the disease is endemic. Using sensitivity SERO analysis we establish that R0 TRANS 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 TRANS. 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 HP due to effective quarantine measures. We provide estimates of R0 and the proportion of asymptomatic TRANS individuals in the population for these countries.

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

    Authors: Mohsin Ali; Mudassar Imran; Adnan Khan

    doi:10.1101/2020.05.29.20116749 Date: 2020-05-29 Source: medRxiv

    We formulate a deterministic epidemic model to study the effects of medication on the transmission TRANS dynamics of Corona Virus Disease MESHD (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 TRANS by extending the SEIR model to include asymptomatic TRANS, quarantined, isolated and medicated population compartments. We calculate the basic reproduction number TRANS R_0 TRANS and show that for R_0 TRANS<1 the disease dies out and for R_0 TRANS>1 the disease is endemic. Using sensitivity SERO analysis we establish that R_0 TRANS 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 R_0 TRANS. 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 HP due to effective quarantine measures. We provide estimates of R_0 TRANS and the proportion of asymptomatic TRANS individuals in the population for these countries.

    Modelling the impact of Plasma SERO Therapy and Immunotherapy for Recovery of COVID-19 Infected Individuals

    Authors: Nita H Shah; Ankush H Suthar; Ekta N Jayswal; Nehal Shukla; Jagdish Shukla

    doi:10.1101/2020.05.23.20110973 Date: 2020-05-24 Source: medRxiv

    Since the first case of COVID-19 was detected in Wuhan, China in December 2019, COVID-19 has become a pandemic causing a global economic and public health emergency. There is no known treatment or vaccine available for COVID-19 to date. Immunotherapy and plasma SERO therapy has been used with satisfactory efficacy over the past two decades in many viral infections MESHD like SARS ( Systemic Acute Respiratory Syndrome MESHD), MERS MESHD ( Middle East Respiratory Syndrome MESHD), and H1N1. Limited data from China show clinical benefit, radiological resolution, reduction in viral loads, and improved survival. Our aim is to create a mathematical model for COVID-19 transmission TRANS and then apply various control parameters to see their effects on recovery from COVID-19 disease. We have formulated a system of non-linear ordinary differential equations, calculated basic reproduction R0 TRANS, and applied five different controls (self-isolation, quarantine, herd immunity, immunotherapy, plasma SERO therapy) to test the effectiveness of control strategy. Control optimality was checked by Lagrangian functions. Numerical simulations and bifurcation analyses were carried out. The study concludes that the COVID-19 outbreak can be controlled up to a significant level three weeks after applying all the control strategies together. These strategies lead to a reduction in hospitalization and a rise in recovery from infection. Immunotherapy is highly effective initially in hospitalized infected individuals however better results were seen in the long term with plasma SERO therapy.

    A model for 2019-nCoV infection MESHD with treatment

    Authors: Amar Nath Chatterjee; Fahad Al Basir

    doi:10.1101/2020.04.24.20077958 Date: 2020-04-29 Source: medRxiv

    The current emergence of coronavirus (2019-nCoV or SARS-CoV-2) puts the world in threat. The structural research on the receptor recognition by SARS-CoV-2 has identified the key interactions between SARS-CoV-2 spike protein and its host (epithelium cell) receptor, also known as angiotensin-converting enzyme 2 (ACE2). It controls both the cross-species and human-to-human transmissions TRANS of SARS-CoV-2. In view of this, we propose and analyze a mathematical model for investigating the effect of CTL responses over the viral mutation to control the viral infection MESHD when a post-infection immunostimulant drug (Pidotimode) is administered at regular intervals. Dynamics of the system with and without impulses have been analyzed using the basic reproduction number TRANS. This study shows that proper dosing interval and drug dose both are important to eradicate the viral infection MESHD.

    Novel Corona virus Disease infection MESHD in Tunisia: Mathematical model and the impact of the quarantine strategy

    Authors: Haifa Ben Fredj; Farouk Chérif

    id:2004.10321v1 Date: 2020-04-21 Source: arXiv

    In this paper, we propose a new model for the dynamics of COVID-19 infections. Our approach consists of seven phenotypes: the susceptible humans, exposed humans, infectious humans, the recovered humans, the quarantine population, the recovered-exposed and deceased population. We proved first through mathematical approach the positivity, boundness and existence of a solution to considered model. We also studied the existence of the disease free equilibrium and corresp onding stability. Hence, the actual reproduction number TRANS was calculated . We analyzed the dependence of basic reproductions R_0 TRANS on the confidence of our model. Our work shows, in particular, that the disease will decrease out if the number of reproduction TRANS was less than one. Moreover, the impact of the quarantine strategies to reduce the spread of this disease TRANS is discussed. The theoretical results are validated by some numerical simulations of the system of the epidemic's differential equations.

    The Impact of Isolation on the Transmission TRANS of COVID-19 and Estimation of Potential Second Epidemic in China

    Authors: Haitao Song; Fang Liu; Feng Li; Xiaochun Cao; Hao Wang; Zhongwei Jia; Huaiping Zhu; Michael Li; Wei Lin; Hong Yang; Jianghong Hu; Zhen Jin

    id:10.20944/preprints202003.0456.v1 Date: 2020-03-31 Source: Preprints.org

    The first case of Corona Virus Disease MESHD 2019 (COVID-19) was reported in Wuhan, China in December 2019. Since then, COVID-19 has quickly spread out to all provinces in China and over 150 countries or territories in the world. With the first level response to public health emergencies (FLRPHE) launched over the country, the outbreak of COVID-19 in China is achieving under control in China. We develop a mathematical model based on epidemiology of COVID-19, incorporating the isolation of healthy people, confirmed cases TRANS and close contacts TRANS. We calculate the basic reproduction numbers TRANS 2.5 in China (excluding Hubei province) and 2.9 in Hubei province with the initial time on January 30 which show the severe infectivity of COVID-19, and verify that the current isolation method effectively contains the transmission TRANS of COVID-19. Under the isolation of healthy people, confirmed cases TRANS and close contacts TRANS, we find a noteworthy phenomenon that is the potential second epidemic of COVID-19, and estimate the peak time and value and the cumulative number of cases. Simulations show that the isolation of close contacts TRANS tracked measure can efficiently contain the transmission TRANS of the potential second epidemic of COVID-19. With isolation of all susceptible people or all infected people MESHD or both, there is no potential second epidemic of COVID-19. Furthermore, resumption of work and study can increase the transmission risk TRANS of the potential second epidemic of COVID-19.

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MeSH Disease
Human Phenotype
Transmission
Seroprevalence


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