Corpus overview


Overview

MeSH Disease

Human Phenotype

Falls (10)

Pneumonia (6)

Hypertension (1)

Fever (1)


Transmission

Seroprevalence
    displaying 21 - 30 records in total 149
    records per page




    An Analysis of Outbreak Dynamics and Intervention Effects for COVID-19 Transmission TRANS in Europe

    Authors: Wei Wang

    doi:10.1101/2020.07.21.20158873 Date: 2020-07-25 Source: medRxiv

    As of March 13, 2020, Europe became the center of COVID-19 pandemic. In order to prevent further spread and slow down the increase in confirmed cases TRANS and deaths MESHD, many countries in European Union have taken some interventions since mid-March. In this study, a metapopulation model was used to model the outbreak of COVID-19 in Europe and the effectiveness of these interventions were also estimated. The findings suggested that many countries successfully kept the reproduction number TRANS R_t less than 1 (e.g., Belgium, Germany, Spain, and France) while other countries exhibited R_t greater than 1 (e.g., United Kingdom, Cyprus). Based on the assumed reopen strategy, this study also revealed that a 2-week delay in response predicted approximately 2,000 deaths and 200,000 cases (daily peak value), while a 3-week delay predicted approximately 5,000 deaths MESHD and 600,000 cases (daily peak value). Therefore, a quick response upon signs of a re-emerging pandemic in the world is highly imperative to mitigate potential loss of life and to keep transmission TRANS of Covid-19 under control.

    The COVID-19 outbreak in Sichuan, China: epidemiology and impact of interventions

    Authors: Quanhui Liu; Ana I Bento; Kexin Yang; Hang Zhang; Xiaohan Yang; Stefano Merler; Alessandro Vespignani; Jiancheng Lv; Hongjie Yu; Wei Zhang; Tao Zhou; Marco Ajelli

    doi:10.1101/2020.07.20.20157602 Date: 2020-07-21 Source: medRxiv

    In January 2020, a COVID19 outbreak was detected in Sichuan Province of China. The aim of this work is to characterize the epidemiology of the Sichuan outbreak and estimate the impact of the performed interventions. We analyzed patient records for all laboratory confirmed cases TRANS reported in the province for the period of January 21 to March 16, 2020. To estimate the basic and daily reproduction numbers TRANS, we used a Bayesian framework. In addition, we estimate the number of cases averted by the implemented control strategies. The outbreak resulted in 539 confirmed cases TRANS, lasted less than two months, and no further local transmission TRANS was detected after February 27. The median age TRANS of local cases was 8 years older than that of imported cases. Severity of symptoms increased with age TRANS. We estimated R0 TRANS at 2.4 (95% CI: 1.6-3.7). The epidemic was self sustained for about 3 weeks before going below the epidemic threshold 3 days after the declaration of a public health emergency by Sichuan authorities. Our findings indicate that, were the control measures be adopted four weeks later, the epidemic could have lasted 49 days longer (95%CI: 31-68 days), causing 9,216 (95%CI: 1,317-25,545) more cases and possibly overwhelming Sichuan healthcare system.

    Epidemiological Profile and Transmission TRANS Dynamics of COVID-19 in the Philippines

    Authors: Nel Jason Ladiao Haw; Jhanna Uy; Karla Therese L. Sy

    doi:10.1101/2020.07.15.20154336 Date: 2020-07-20 Source: medRxiv

    The Philippines confirmed local transmission TRANS of COVID-19 on 7 March 2020. We described the characteristics and epidemiological time-to-event distributions for laboratory- confirmed cases TRANS in the Philippines. The median age TRANS of 8,212 cases was 46 years (IQR: 32-61), with 46.2% being female TRANS and 68.8% living in the National Capital Region. Health care workers represented 24.7% of all detected infections. Mean length of hospitalization for those who were discharged or died were 16.00 days (95% CI: 15.48, 16.54) and 7.27 days (95% CI: 6.59, 8.24). Mean duration of illness was 26.66 days (95% CI: 26.06, 27.28) and 12.61 days (95% CI: 11.88, 13.37) for those who recovered or died. Mean serial interval TRANS was 6.90 days (95% CI: 5.81, 8.41). Epidemic doubling time pre-quarantine (11 February and 19 March) was 4.86 days (95% CI: 4.67, 5.07) and the reproductive number TRANS was 2.41 (95% CI: 2.33, 2.48). During quarantine (March 20 to April 9), doubling time was 12.97 days (95% CI: 12.57, 13.39) and the reproductive number TRANS was 0.89 (95% CI: 0.78, 1.02).

    Epidemiological aspects of COVID-19 disease in India during nationwide lockdown phase- An empirical data-based analysis and its implications on interrupting the transmission TRANS

    Authors: PERUMAL VANAMAIL

    doi:10.1101/2020.07.16.20155903 Date: 2020-07-17 Source: medRxiv

    Background: Covid-19 disease is pandemic in more than 85% of the countries in the world, with about 10 million cases and 0.5 million deaths as on July 2, 2020. In India reporting of the first case was on January 30, 2020, and to prevent rapid community spread of the disease TRANS nationwide lockdown phase was imposed from March 25- June 1, 2020. Our objective was to assess various epidemiological measures during the lockdown phase. Methods: We used daily reporting of confirmed cases TRANS by the Ministry of Health and Family Welfare, Government of India during the period March 19-June 1, 2020. Using statistical packages STATA version 16.0 and R-packages in R-version 4.0, we fitted statistical distributions, estimated generation time and Basic Reproduction numbers TRANS. Results: During the lockdown phase, the daily per cent increase in the cumulative number of cases showed negative exponential growth with 0.022 as an instantaneous rate of decrease. Day specific incidence rate per million revealed the exponential pattern with 0.069 as the instantaneous rate of increase per day, which accounted for the doubling time of the disease (10 days; 95% CI: 9.25-10.93). Case fatality rate (2.92%; 95% CI: 2.82% -3.02%) and overall death rate was 1.14 (95% CI: 0.87-1.41) per million. were abysmally low. Statistical distribution fitting of new cases found to be satisfactory with Gamma distribution. Basic reproduction numbers TRANS 1.83 (95% CI: 1.82-1.83) was less. Conclusion: In India, with a population density of about 450 per Km2, the virulent of COVID-19 transmission TRANS was interrupted significantly with 70 days lockdown during the early transmission TRANS stage. A great decline could be seen in all the epidemiological indices compared to the index noted during the same period in the severely affected countries.

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

    Authors: Altahir A. Altahir; Nirbhay Mathur; Loshini Thiruchelvam; Ghulam E. Mustafa Abro; Syaimaa S. M. Radzi; Sarat C Dass; Balvinder Singh Gill; Patrick Sebastian; Saiful A. Zulkifli; Vijanth S. Asirvadam

    doi:10.1101/2020.07.17.208371 Date: 2020-07-17 Source: bioRxiv

    After 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 TRANS and more than half a million are dead around the world. This virus also attached Malaysia MESHD in its immature stage where 8718 cases were confirmed TRANS 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 MESHD dynamic modeling (SEIR) is used to estimate the epidemic spread in Malaysia. The main assumption is to update the reproduction number TRANS 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

    A comprehensive analysis of R0 TRANS with different lockdown phase during covid-19 in India

    Authors: Mayank Chhabra; Tushant Agrawal

    doi:10.1101/2020.07.10.20150631 Date: 2020-07-11 Source: medRxiv

    Background: World Health organization declared Covid-19 as an outbreak, hence preventive measure like lockdown should be taken to control the spread of infection MESHD. This study offers an exhaustive analysis of the reproductive number TRANS ( R0 TRANS) in India with major intervention for COVID-19 outbreaks and analysed the lockdown effects on the Covid-19. Methodology: Covid-19 data extracted from Ministry of Health and Family Welfare, Government of India. Then, a novel method implemented in the incidence and Optimum function in desolve package to the data of cumulative daily new confirmed cases TRANS for robustly estimating the reproduction number TRANS in the R software. Result: Analysis has been seen that the lockdown was really quite as effective, India has already shown a major steady decline. The growth rate has fluctuated about 20 percent with trend line projections in various lockdown. A comparative analysis gives an idea of decline in value of R0 TRANS from 1.73 to 1.08. Annotation plot showing the predicted R0 TRANS values based on previous lockdown in month of June and July. Conclusion: Without lockdown, the growth might not have been contained in India and may have gone into the exponential zone. We show that, the lockdown in India was fairly successful. The effect partial lifting of the lockdown (unlock) is also seen in the results, in terms of increment in R0 TRANS values. Hence this study provides a platform for policy makers and government authorities for implementing the strategies to prevent the spread of infection MESHD.

    Modelling COVID-19 cases in Nigeria: Forecasts, uncertainties, projections and the link with weather

    Authors: Adeyeri O.E.; Oyekan K.S.A.; Ige S.O.; Akinbobola A.; Okogbue E.C.

    doi:10.21203/rs.3.rs-41193/v1 Date: 2020-07-11 Source: ResearchSquare

    The World Health Organization (WHO) declared COVID-19 a global pandemic on 11 March 2020 due to its global spread. In Nigeria, the first case was documented on 27 February 2020. Since then, it has spread to most parts of the country. This study models, forecasts and projects COVID-19 incidence, cumulative incidence and death MESHD cases in Nigeria using six estimation methods i.e. the attack rate TRANS, maximum likelihood, exponential growth, Markov chain monte Carlo (MCMC), time-dependent and the sequential Bayesian approaches. A sensitivity SERO analysis with respect to the mean generation time is used to quantify the associated reproduction number TRANS uncertainties. The relationship between the COVID-19 incidence and five meteorological variables are further assessed. The result shows that the highest incidences are recorded in days with either religious activities or market days while the weekday trend decreases towards the weekend. It is also established that COVID-19 incidence significantly increases with increasing sea level pressure (0.7 correlation coefficient) and significantly decreases with increasing maximum temperature (-0.3 correlation coefficient). Also, selecting an optimal period for reproduction number TRANS estimates reduces the variability between estimates. As an example, in the EG approach, the epidemic curve that optimally fits the exponential growth is between 1- and 53-time units with reproduction number TRANS estimate of 1.60 [1.58; 1.62] at 95% confidence interval. However, this optimal reproduction number TRANS estimate is different from the default reproduction number TRANS estimate.  Using the MCMC approach, the correlation coefficients between the observed and forecasted incidence, cumulative death MESHD and cumulative confirmed cases TRANS are 0.66, 0.92 and 0.90 respectively. The projections till December shows values approaching 1,000,000, 120,000 and 3,000,000 respectively. Therefore, timely intervention and effective preventive measures are immediately needed to mitigate a full-scale epidemic in the country. 

    Transmission TRANS dynamics and control measures of COVID-19 outbreak in China: a modelling study

    Authors: XuSheng Zhang; Emilia Vynnycky; Andre Charlett; Daniela de Angelis; Zhengji Chen; Wei Liu

    doi:10.1101/2020.07.09.20150086 Date: 2020-07-11 Source: medRxiv

    COVID-19 is reported to have been effectively brought under control in China at its initial start place. To understand the COVID-19 outbreak in China and provide potential lessons for other parts of the world, in this study we combine a mathematical modelling with multiple datasets to estimate its transmissibility TRANS and severity and how it was affected by the unprecedented control measures. Our analyses show that before 29th January 2020, the ascertainment rate is 6.9%(95%CI: 3.5 - 14.6%); then it increased to 41.5%(95%CI: 30.6 - 65.1%). The basic reproduction number TRANS ( R0 TRANS) was 2.23(95%CI: 1.86 - 3.22) before 8th February 2020; then it dropped to 0.04(95%CI: 0.01 - 0.10). This estimation also indicates that the effect on transmissibility TRANS of control measures taken since 23rd January 2020 emerged about two weeks late. The confirmed case TRANS fatality rate is estimated at 4.41%(95%CI: 3.65 - 5.30%). This shows that SARS-CoV-2 virus is highly transmissible but less severe than SARS-CoV-1 and MERS-CoV. We found that at the early stage, the majority of R0 TRANS comes from the undetected infected people. This implies that the successful control in China was achieved through decreasing the contact rates among people in general populations and increasing the rate of detection and quarantine of the infected cases.

    Undocumented infectives in the Covid-19 pandemic

    Authors: Maurizio Melis; Roberto Littera

    doi:10.1101/2020.07.09.20149682 Date: 2020-07-11 Source: medRxiv

    Background. A crucial role in epidemics is played by the number of undetected infective individuals who continue to circulate and spread the disease TRANS. Epidemiological investigations and mathematical models have revealed that the rapid diffusion of Covid-19 can mostly be attributed to the large percentage of undocumented infective individuals who escape testing. Methods. The dynamics of an infection can be described by the SIR model, which divides the population into susceptible (S), infective (I) and removed (R) subjects. In particular, we exploited the Kermack and McKendrick epidemic MESHD model which can be applied when the population is much larger than the fraction of infected subjects. Results. We proved that the fraction of undocumented infectives, in comparison to the total number of infected subjects, is given by 1-1/ R0 TRANS , where R0 TRANS is the basic reproduction number TRANS. Its mean value R0=2.10 (2.09-2.11) in three Italian regions for the Covid-19 epidemic yielded a percentage of undetected infectives of 52.4% (52.2% - 52.6%) compared to the total number of infectives. Conclusions. Our results, straightforwardly obtained from the SIR model, highlight the role played by undetected carriers TRANS in the transmission TRANS and spread of the SARS-CoV-2 infection MESHD. Such evidence strongly recommends careful monitoring of the infective population and ongoing adjustment of preventive measures for disease control until a vaccine becomes available.

    Estimating the time-varying reproduction number TRANS of COVID-19 with a state-space method

    Authors: Shinsuke Koyama; Taiki Horie; Shigeru Shinomoto

    doi:10.1101/2020.07.09.20150219 Date: 2020-07-11 Source: medRxiv

    After slowing down the spread of the novel coronavirus COVID-19, many countries have started to relax their severe confinement measures in the face of critical damage to socioeconomic structures. At this point, it is desirable to monitor the degree to which political measures or social affairs have exerted influence on the spread of disease TRANS; however, tracing TRANS back individual transmission TRANS of infections whose incubation periods TRANS are long and highly variable seems to be difficult. Nevertheless, it may be possible to estimate the changes that may have occurred in the past, if we can suitably fit a proper model to daily event-occurrences. We have devised a state-space method for fitting the Hawkes process to a given dataset of daily confirmed cases TRANS. This method detects changes occurring in the spread of the contagion in each country. Furthermore, this method can assess the impact of social events in terms of the temporally varying reproduction number TRANS representing the average number of cases directly caused by a single infected case. This information might serve as a reference for the behavioral guidelines that should be adopted according to the varying risk of infection TRANS risk of infection TRANS infection MESHD.

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MeSH Disease
Human Phenotype
Transmission
Seroprevalence


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