Corpus overview


Overview

MeSH Disease

Infections (554)

Disease (464)

Death (402)

Coronavirus Infections (276)

Pneumonia (109)


Human Phenotype

Pneumonia (113)

Fever (109)

Cough (88)

Fatigue (28)

Hypertension (20)


Transmission

Seroprevalence
    displaying 621 - 630 records in total 1146
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    Early viral clearance and antibody SERO kinetics of COVID-19 among asymptomatic TRANS carriers TRANS

    Authors: Zheng Zhang; Tongyang Xiao; Yanrong Wang; Jing Yuan; Haocheng Ye; Lanlan Wei; Haiyan Wang; Xuejiao Liao; Shen Qian; Zhaoqin Wang; Lei Liu

    doi:10.1101/2020.04.28.20083139 Date: 2020-05-02 Source: medRxiv

    Background Asymptomatic TRANS carriers TRANS contribute to the spread of Coronavirus Disease MESHD 2019 (COVID-19), but their clinical characteristics, viral kinetics, and antibody SERO responses remain unclear. Methods A total of 56 COVID-19 patients without symptoms at admission and 19 age TRANS-matched symptomatic patients were enrolled. RNA of SARS-CoV-2 was tested using transcriptase quantitative PCR, and the total antibodies SERO (Ab), IgG, IgA and IgM against the SARS-CoV-2 were tested using Chemiluminescence Microparticle Immuno Assay. Results Among 56 patients without symptoms at admission, 33 cases displayed symptoms and 23 remained asymptomatic TRANS throughout the follow-up period. 43.8% of the asymptomatic TRANS carriers TRANS were children TRANS and none of the asymptomatic TRANS cases had recognizable changes in C-reactive protein or interleukin-6, except one 64-year-old patient. The initial threshold cycle value of nasopharyngeal SARS-CoV-2 in asymptomatic TRANS carriers TRANS was similar to that in pre-symptomatic and symptomatic patients, but the communicable period of asymptomatic TRANS carriers TRANS (9.63 days) was shorter than pre-symptomatic patients (13.6 days). There was no obvious differences of the seropositive conversion rate of total Ab, IgG, and IgA among the three groups, though the rates of IgM varied largely. The average peak IgG and IgM COI of asymptomatic TRANS cases was 3.5 and 0.8, respectively, which is also lower than those in symptomatic patients with peaked IgG and IgM COI of 4.5 and 2.4 (p <0.05). Conclusion Young COVID-19 patients seem to be asymptomatic TRANS cases with early clearance of SARS-CoV-2 and low levels of IgM generation but high total Ab, IgG and IgA. Our findings provide empirical information for viral clearance and antibody SERO kinetics of asymptomatic TRANS COVID-19 patients.

    How and when to end the COVID-19 lockdown: an optimisation approach

    Authors: Thomas Rawson; Tom Brewer; Dessislava Veltcheva; Chris Huntingford; Michael B. Bonsall

    doi:10.1101/2020.04.29.20084517 Date: 2020-05-02 Source: medRxiv

    Countries around the world are in a state of lockdown to help limit the spread of SARS-CoV-2. However, as the number of new daily confirmed cases TRANS begins to decrease, governments must decide how to release their populations from quarantine as efficiently as possible without overwhelming their health services. We applied an optimal control framework to an adapted Susceptible-Exposure- Infection MESHD-Recovery (SEIR) model framework to investigate the efficacy of two potential lockdown release strategies, focusing on the UK population as a test case. To limit recurrent spread, we find that ending quarantine for the entire population simultaneously is a high-risk strategy, and that a gradual re-integration approach would be more reliable. Furthermore, to increase the number of people that can be first released, lockdown should not be ended until the number of new daily confirmed cases TRANS reaches a sufficiently low threshold. We model a gradual release strategy by allowing different fractions of those in lockdown to re-enter the working non-quarantined population. Mathematical optimisation methods, combined with our adapted SEIR model, determine how to maximise those working while preventing the health service from being overwhelmed. The optimal strategy is broadly found to be to release approximately half the population two-to-four weeks from the end of an initial infection MESHD peak, then wait another three-to-four months to allow for a second peak before releasing everyone else. We also modelled an ''on-off'' strategy, of releasing everyone, but re-establishing lockdown if infections MESHD become too high. We conclude that the worst-case scenario of a gradual release is more manageable than the worst-case scenario of an on-off strategy, and caution against lockdown-release strategies based on a threshold-dependent on-off mechanism. The two quantities most critical in determining the optimal solution are transmission TRANS rate and the recovery rate, where the latter is defined as the fraction of infected people in any given day that then become classed as recovered. We suggest that the accurate identification of these values is of particular importance to the ongoing monitoring of the pandemic.

    An Epidemic Model SIPHERD and its application for prediction of the spread of COVID-19 infection MESHD for India and USA

    Authors: Ashutosh Mahajan; Ravi Solanki; A. S. Namitha

    id:2005.00921v2 Date: 2020-05-02 Source: arXiv

    We propose an epidemic model SIPHERD in which three categories of infection MESHD carriers TRANS Symptomatic, Purely Asymptomatic TRANS, and Exposed are considered with different rates of transmission TRANS of infection MESHD that are taken dependent on the lockdown and social distancing. The rate of detection of the infected carriers TRANS is taken dependent on the tests done per day. The model is applied for the COVID outbreak in Germany and South Korea to validate its predictive capabilities and then applied to India and the United States for the prediction of its spread with different lockdown situations and testing in the coming months.

    Using Supervised Machine Learning and Empirical Bayesian Kriging to reveal Correlates and Patterns of COVID-19 Disease MESHD outbreak in sub-Saharan Africa: Exploratory Data Analysis

    Authors: Amobi Andrew Onovo; Akinyemi Atobatele; Abiye Kalaiwo; Christopher Obanubi; Ezekiel James; Pamela Gado; Gertrude Odezugo; Doreen Magaji; Dolapo Ogundehin; Michele Russell

    doi:10.1101/2020.04.27.20082057 Date: 2020-05-02 Source: medRxiv

    Introduction: Coronavirus disease MESHD 2019 (COVID-19) is an emerging infectious disease MESHD that was first reported in Wuhan, China, and has subsequently spread worldwide. Knowledge of coronavirus-related risk factors can help countries build more systematic and successful responses to COVID-19 disease MESHD outbreak. Here we used Supervised Machine Learning and Empirical Bayesian Kriging (EBK) techniques to reveal correlates and patterns of COVID-19 Disease MESHD outbreak in sub-Saharan Africa (SSA). Methods: We analyzed time series aggregate data compiled by Johns Hopkins University on the outbreak of COVID-19 disease MESHD across SSA. COVID-19 data was merged with additional data on socio-demographic and health indicator survey data for 39 of SSA 48 countries that reported confirmed cases TRANS and deaths MESHD from coronavirus between February 28, 2020 through March 26, 2020. We used supervised machine learning algorithm, Lasso for variable selection and statistical inference. EBK was used to also create a raster estimating the spatial distribution of COVID-19 disease MESHD outbreak. Results: The lasso Cross-fit partialing out predictive model ascertained seven variables significantly associated with the risk of coronavirus infection MESHD (i.e. new HIV infections MESHD among pediatric, adolescent, and middle- aged TRANS adult TRANS PLHIV, time (days), pneumococcal conjugate-based vaccine, incidence of malaria MESHD and diarrhea MESHD diarrhea HP treatment). Our study indicates, the doubling time in new coronavirus cases was 3 days. The steady three-day decrease in coronavirus outbreak rate of change (ROC) from 37% on March 23, 2020 to 23% on March 26, 2020 indicates the positive impact of countries' steps to stymie the outbreak. The interpolated maps show that coronavirus is rising every day and appears to be severely confined in South Africa. In the West African region (i.e. Burkina Faso, Ghana, Senegal, CotedIviore, Cameroon, and Nigeria), we predict that new cases and deaths MESHD from the virus are most likely to increase. Interpretation: Integrated and efficiently delivered interventions to reduce HIV, pneumonia MESHD pneumonia HP, malaria MESHD and diarrhea MESHD diarrhea HP, are essential to accelerating global health efforts. Scaling up screening and increasing COVID-19 testing capacity across SSA countries can help provide better understanding on how the pandemic is progressing and possibly ensure a sustained decline in the ROC of coronavirus outbreak. Funding: Authors were wholly responsible for the costs of data collation and analysis.

    Chinese effective control and other countries uncharted challenge against COVID-19: an epidemiological and modelling study

    Authors: Lingling Zheng; Kang Qin; Xiujuan Chen; Shuai Huang; Dong Liu; Weiyao Liao; Huimin Xia; Jinling Tang; Huiying Liang

    doi:10.1101/2020.04.28.20083899 Date: 2020-05-02 Source: medRxiv

    Background: On the present trajectory, COVID is inevitably becoming a global epidemic, leading to concerns regarding the pandemic potential in China and other countries. Objective: In this study, we use the time-dependent reproduction number TRANS (Rt) to comprise the COVID transmissibility TRANS across different countries. Methods: We used data from Jan 20, 2019, to Feb 29, 2020, on the number of newly confirmed cases TRANS, obtained from the reports published by the CDC, to infer the incidence of infectious over time. A two-step procedure was used to estimate the Rt. The first step used data on known index- secondary cases TRANS pairs, from publicly available case reports, to estimate the serial interval TRANS distribution. The second step estimated the Rt jointly from the incidence data and the information data in the first step. Rt was then used to simulate the epidemics across all major cities in China and typical countries worldwide. Results: Based on a total of 126 index- secondary cases TRANS pairs from 4 international regions, we estimated that the serial interval TRANS for SARS-2-CoV was 4.18 (IQR 1.92 - 6.65) days. Domestically, Rt of China, Hubei province, Wuhan had fallen HP below 1.0 on 9 Feb, 10 Feb and 13 Feb (Rt were 0.99 {+/-} 0.02, 0.99 {+/-} 0.02 and 0.96 {+/-} 0.02), respectively. Internationally, as of 26 Feb, statistically significant periods of COVID spread (Rt >1) were identified for most regions, except for Singapore (Rt was 0.92 {+/-} 0.17). Conclusions: The epidemic in China has been well controlled, but the worldwide pandemic has not been well controlled. Worldwide preparedness and vulnerability against COVID-19 should be regarded with more care.

    Rapid adaptation of SARS-CoV-2 in BALB/c mice: Novel mouse model for vaccine efficacy

    Authors: Hongjing Gu; Qi Chen; Guan Yang; Lei He; Hang Fan; Yong-qiang Deng; Yanxiao Wang; Yue Teng; Zhongpeng Zhao; Yujun Cui; Yuchang Li; Xiao-Feng Li; Jiangfan Li; Nana Zhang; Xiaolan Yang; Shaolong Chen; Guangyu Zhao; Xiliang Wang; Deyan Luo; Hui Wang; Xiao Yang; Yan Li; Gencheng Han; Yuxian He; Xiaojun Zhou; Shusheng Geng; Xiaoli Sheng; Bojiang Shi; Shihui Sun; Cheng-Feng Qin; Yusen Zhou

    doi:10.1101/2020.05.02.073411 Date: 2020-05-02 Source: bioRxiv

    Coronavirus disease MESHD 2019 (COVID-19) threatens global public health and economy. In order to develop safe and effective vaccines, suitable animal models must be established. Here we report the rapid adaption of SARS-CoV-2 in BALB/c mice, based on which a convenient, economical and effective animal model was developed. Specifically, we found that mouse-adapted SARS-CoV-2 at passage 6 (MACSp6) efficiently infected both aged TRANS and young wild-type BALB/c mice, resulting in moderate pneumonia MESHD pneumonia HP as well as inflammatory responses. The elevated infectivity of MACSp6 in mice could be attributed to the substitution of a key residue (N501Y) in the receptorbinding domain (RBD). Using this novel animal model, we further evaluated the in vivo protective efficacy of an RBD-based SARS-CoV-2 subunit vaccine, which elicited highly potent neutralizing antibodies SERO and conferred full protection against SARS-CoV-2 MACSp6 challenge. This novel mouse model is convenient and effective in evaluating the in vivo protective efficacy of SARS-CoV-2 vaccine. SummaryThis study describes a unique mouse model for SARS-CoV-2 infection MESHD infection and confirms TRANS and confirms protective efficacy of a SARS-CoV-2 RBD subunit vaccine.

    Reduced COVID-19-Related Critical Illness MESHD and Death MESHD, and High Risk of Epidemic Resurgence, After Physical Distancing in Ontario, Canada

    Authors: Ashleigh Tuite; Amy L Greer; Steven De Keninck; David N Fisman

    doi:10.1101/2020.04.29.20084475 Date: 2020-05-02 Source: medRxiv

    We explored the impact of physical distancing measures on COVID-19 transmission TRANS in the population of Ontario, Canada using a previously described age TRANS- and health-status stratified transmission TRANS model. The model was fit to confirmed cases TRANS occupying intensive care unit (ICU) beds and mortality among hospitalized COVID-19 cases for the time period 19 March to 26 April 2020. We projected that mortality would have been 4.6-fold what was observed had physical distancing measures not been implemented in the province. Relaxation of physical distancing measures without compensatory increases in case detection, isolation, and/or contact tracing TRANS was projected to result in resurgence of disease MESHD activity. Return to normal or near-normal levels of contact would rapidly result in cases exceeding ICU capacity. Maintaining physical distancing for a longer period of time, allowing for the initial wave of infections MESHD to subside, delayed this resurgence, but the level of contacts post-restrictive distancing was the major factor determining how quickly ICU capacity was expected to be overwhelmed. Using a model, we demonstrate the marked impact strong public health measures had in reducing ICU admissions and mortality in Ontario. We also show that this hard-earned success is tenuous: relaxation of physical distancing measures in the near-term is projected to result in a rapid resurgence of disease MESHD activity.

    Estimation of seroprevalence SERO of novel coronavirus disease MESHD (COVID-19) using preserved serum SERO at an outpatient setting in Kobe, Japan: A cross-sectional study.

    Authors: Asako Doi; Kentaro Iwata; Hirokazu Kuroda; Toshikazu Hasuike; Seiko Nasu; Aya Kanda; Tomomi Nagao; Hiroaki Nishioka; Keisuke Tomii; Takeshi Morimoto; Yasuki Kihara

    doi:10.1101/2020.04.26.20079822 Date: 2020-05-01 Source: medRxiv

    Summary Background Coronavirus disease MESHD 2019 (COVID-19) pandemic caused by SARS-CoV-2 has been affecting many people on earth and our society. Japan is known to have relatively less number of infections MESHD as well as deaths MESHD among developed nations. However, accurate prevalence SERO of COVID-19 in Japan remains unknown. Therefore, we conducted a cross-sectional study to estimate seroprevalence SERO of SARS-CoV-2 infection MESHD. Methods We conducted a cross-sectional serologic testing SERO for SARS-CoV-2 antibody SERO using 1,000 samples from patients at outpatient settings who visited the clinic from March 31 to April 7, 2020, stratified by decade of age TRANS and sex. Results There were 33 positive IgG among 1,000 serum samples SERO (3.3%, 95%CI: 2.3-4.6%). By applying this figure to the census of Kobe City (poplation: 1,518,870), it is estimated that the number of people with positive IgG be 50,123 (95%CI: 34,934-69,868). Age TRANS and sex adjusted prevalence SERO of positivity was 2.7% (95%CI 1.8-3.9%), and the estimated number of people with positive IgG was 40,999 (95%CI: 27,333-59,221). These numbers were 396 to 858 fold more than confirmed cases TRANS with PCR testing in Kobe City. Conclusions Our cross-sectional serological study suggests that the number of people with seropositive for SARS-CoV-2 infection MESHD in Kobe, Japan is far more than the confirmed cases TRANS by PCR testing.

    Rapid review of the existing COVID-19 Case Definitions: A Bayesian Approach model to COVID-19 Case Definitions: A Research Article

    Authors: Emad Karimian Rad; Shahram Yazdani; Zeynab Foroughi; Ali-Akbar Haghdoost; Hadi Jabali; Alireza Hajikhani; Maryam Hoseini Abardeh

    doi:10.21203/rs.3.rs-26337/v1 Date: 2020-05-01 Source: ResearchSquare

    Background Since December 2019, the novel coronavirus disease MESHD (COVID-19) has rapidly spread around the world leading to a pandemic with more than 3,000,000 infected people and more than 200,000 death MESHD. Several case definitions have been released and revised by countries and organizations. However, collectivization of case definitions has not been fully investigated.Methods In this study, we rapidly reviewed existing COVID-19 case definitions, finally a dynamic case definition algorithm was provided by using Bayesian theorem models of diagnosis.Results Our results showed categorization as suspected, probable, and confirmed cases TRANS, is used in majority of case definitions. Furthermore, the criteria for suspected cases and laboratory testing priority was a point of argument. Due to pandemic situation and resource limitation, diagnostic tests were rationed and mainly administered to a selected population, thus it was shown that the fraction of positive test results does not reflect the total infection MESHD rate of the population. Case definitions for COVID-19 is changing as we learn more about the disease MESHD. RT-PCR and CT Scan of lung seem to be beneficial in COVID-19 diagnosis and combing them with epidemiological criteria helps us in better understanding of the disease MESHD.Conclusion Based on our results, in the current case definitions, only symptomatic patients categorized and tested as a susceptible case. While the majority of COVID-19 cases are asymptomatic TRANS carriers TRANS of the disease MESHD, thus making the prevention more challenging. Dynamic statistical models can provide new insights into surveillance systems.

    A first study on the impact of containment measure on COVID-19 spread in Morocco

    Authors: Aayah Hammoumi; Redouane Qesmi

    doi:10.1101/2020.04.26.20080770 Date: 2020-05-01 Source: medRxiv

    Background: Since the appearance of the first case of COVID-19 in Morocco, the cumulative number of reported infectious cases continues to increase and, consequently, the government imposed the containment measure within the country. Our aim is to predict the impact of the compulsory containment on COVID-19 spread. Earlier knowledge of the epidemic characteristics of COVID-19 transmission TRANS related to Morocco will be of great interest to establish an optimal plan-of-action to control the epidemic. Method: Using a Susceptible- Asymptomatic TRANS-Infectious model and the data of reported cumulative confirmed cases TRANS in Morocco from March 2nd to April 9, 2020, we determined the basic and control reproduction numbers TRANS and we estimated the model parameter values. Furthermore, simulations of different scenarios of containment are performed. Results: Epidemic characteristics are predicted according to different rates of containment. The basic reproduction number TRANS is estimated to be 2.9949, with CI(2.6729-3.1485). Furthermore, a threshold value of containment rate, below which the epidemic duration is postponed, is determined. Conclusion: Our findings show that the basic reproduction number TRANS reflects a high speed of spread of the epidemic. Furthermore, the compulsory containment can be efficient if more than 73% of population are confined. However, even with 90% of containment, the end-time is estimated to happen on July 4th which can be harmful and lead to consequent social-economic damages. Thus, containment need to be accompanied by other measures such as mass testing to reduce the size of asymptomatic TRANS population. Indeed, our sensitivity SERO analysis investigation shows that the COVID-19 dynamics depends strongly on the asymptomatic TRANS duration as well as the contact and containment rates. Our results can help the Moroccan government to anticipate the spread of COVID-19 and avoid human loses and consequent social-economic damages as well.

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MeSH Disease
Human Phenotype
Transmission
Seroprevalence


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