Modelling, Simulations and Analysis of the First and Second COVID-19 Epidemics in Beijing

Lee, Min

doi:10.1101/2021.07.04.21259205

Cited by 6 publications

(31 citation statements)

References 23 publications

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“…A recommendation to avoid multiple outbreaks of an epidemic is competent authorities should at least maintain preventive and control measures implemented 7 days after inflection turning point until all new infections have been cleared [3].…”

Section: Discussionmentioning

confidence: 99%

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Summaries, Analysis and Simulations of COVID-19 Epidemics in Shanghai

Min

2022

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Shanghai is the best city to prevent the spread of COVID-19 infection in China. Since February 20, 2020, Shanghai has experienced five waves of COVID-19. Out of a total of 388 patients with COVID-19 symptoms, 381 were cured and seven died. Medical staff achieved zero infection. This paper summarizes, analyzes and simulates COVID-19 epidemics in Shanghai. The simulation results show that for five waves of epidemics, after reaching the infection turning point, the blocking rate of symptomatic infection is over 99%. The administration needs to maintain the prevention and control implemented 7 days after reaching the infection turning point until the new infection goes away.

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Section: Discussionmentioning

confidence: 99%

“…Assume that the dynamics of an epidemic can be described by m-time intervals, which correspond different prevention and control measures, and medical effects. At ith time interval, the model has the form [2,3]:…”

Section: Analysis and Simulations Of Covid-19 Epidemics In Shanghaimentioning

confidence: 99%

Summaries, Analysis and Simulations of COVID-19 Epidemics in Shanghai

Min

2022

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“…In order to estimate numerically the transmission rates and blocking rates to symptomatic and asymptomatic infections, we need to set up mathematic models (similar to [12, 14, 15]) to simulate the dynamics of spread of infection disease. Because we modeling uniformly the epidemic situations appeared in different provinces and regions, the transmission rates β ij of symptomatic infections and asymptomatic infections are changing over different transmission intervals.…”

Section: Analysis and Simulations Of Covid-19 Epidemics In Chinamentioning

confidence: 99%

“…Even on day 90, the blocking rates only reach to about 87.6% and 39.0% (see Table 1), respectively. However, for the first and second epidemics in Beijing and the five wave epidemics in Shanghai, the blocking rates reached to over 95% in one month [13][14][15]. (7) The recovery rates κ(l) and κ a (l) of the symptomatic individuals and asymptomatic individuals waved.…”

Section: Mainland Epidemicsmentioning

confidence: 99%

Summaries, Analysis and Simulations of Recent COVID-19 Epidemics in Mainland China

Lee

2022

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Background: Globally COVID-19 epidemics have caused tremendous disasters. China prevented effectively the spread of COVID-19 epidemics before 2022. Recently Omicron and Delta variants cause a surge in reported COVID-19 infections. Methods: Using differential equations and real word data, this study modelings and simulates COVID-19 epidemic in mainland China, estimates transmission rates, recovery rates, and blocking rates to symptomatic and asymptomatic infections. The transmission rates and recovery rates of the foreign input COVID-19 infected individuals in mainland China have also been studied. Results: The simulation results were in good agreement with the real word data. The recovery rates of the foreign input symptomatic and asymptomatic infected individuals are higher than those of the mainland COVID-19 infected individuals. The blocking rates to symptomatic and asymptomatic mainland infections are lower than those of previous epidemics. The blocking rate implemented between March 24-31, 2022 may not prevent the rapid spreads of COVID-19 epidemics in mainland China. For the foreign input COVID-19 epidemics, the numbers of the current symptomatic individuals and the asymptomatic individuals charged in medical observations have decreased significantly after March 17，2022. Conclusions: Need to implement more strict prevention and control strategies to prevent the spread of COVID-19 mainland infected individuals. Need to keep the present prevention and therapy measures to foreign input COVID-19 infected infections until infected individuals to be cleared.

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“…Assume that the process of the spread of an infectious disease are divided into m time intervals, representing different prevention control measures and treatment efficacy, respectively. Over the lth time interval, the model has the form (similar to [11, 13, 14]): where Θ 1 ( i ) = (1 − θ 1 ( l )) and Θ 2 ( l ) = (1 − θ 2 ( l )) ( l = 1, …, m ) represent the blocking rates to symptomatic and asymptomatic infections, respectively. ( I ) and I a represent the numbers of current symptomatic individuals and current asymptomatic individuals charged in medical observations, respectively.…”

Section: Summaries Analysis and Simulations Of Recent Shanghai Epidemicmentioning

confidence: 99%

Summaries, Analysis and Simulations of Recent COVID-19 Epidemic in Shanghai

Lee

2022

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BackgroundAfter successfully preventing the spread of five wave COVID-19 epidemics in Shanghai, Omicron and Delta variants have been causing a surge COVID-19 infection in this city recently. Summaries, analysis and simulations for this wave epidemic are important issues.MethodsUsing differential equations and real word data, this study modelings and simulates the recent COVID-19 epidemic in Shanghai, estimates transmission rates, recovery rates, and blocking rates to symptomatic and asymptomatic infections, and symptomatic (infected) individuals’ death rates. Visual simulations predict the outcomes of this wave Shanghai epidemic. It compares parallely with the recent mainland China COVID-19 epidemics (RMCE).ResultsThe simulation results were in good agreement with the real word data at the end points of 11 investigated time-intervals. Visual simulation results showed that on the day 90, the number of the current symptomatic (infected) individuals may be between 852 and 7314, the number of the current asymptomatic (infected) individuals charged in the observations may be between 10066 and 50292, the number of the current cumulative recovered symptomatic infected individuals may be between 52070 and 74687, the number of the current cumulative asymptomatic individuals discharged from the medical observations may be between 63509 and 5164535. The number of the died symptomatic individuals may be between 801 and 1226.The transmission rate of the symptomatic infections caused by the symptomatic individuals was much lower than the corresponding average transmission rate of the RMCE.The transmission rate of the asymptomatic infections caused by the symptomatic individuals was much higher than the first 90 day’s average transmission rate of RMCE.The transmission rate of the symptomatic infections caused by the asymptomatic individuals was much lower than the first 60 day’s average transmission rate of RMCE, and was much higher than the last 60 day’s average transmission rate of RMCE.The transmission rate to the asymptomatic infections caused by the asymptomatic individuals was much higher than the corresponding average transmission rate of RMCE.The last 30 days’ average blocking rate to the symptomatic infections were lower than the last 30 days’ average blocking rates of RMCEThe last 30 days’ average blocking rate to the asymptomatic infections were much higher than the last 30 days’ average blocking rate of RMCE. However the first 30 days’ average blocking rate to the asymptomatic infections were much lower than the first 30 days’ average blocking rate of RMCE.The first 37 days’ recovery rates of the symptomatic individuals were much lower than the corresponding first 70 days’ recovery rates of the symptomatic individuals of RMCE. The recovery rates between 38- and 52-days of the symptomatic individuals were much lower than the corresponding the recovery rates between 91- and 115-days of the symptomatic individuals of RMCE. The last week’s recovery rate was similar to the last week’s recovery rate of RMCE.The first 30 days’ average recovery rate recovery rate to the symptomatic individuals were much lower than the first 30 days’ average recovery rate recovery rate of RMCE. The last 30 days’ average recovery rate recovery rate of the symptomatic individuals were still much lower than the last 30 days’ average recovery rate of RMCE.ConclusionsThe last 30 days’ low blocking rates to the symptomatic infections, the first 30 day’s low blocking rates to the symptomatic infections to asymptomatic infections, the low recovery rates of the symptomatic and asymptomatic individuals, and the high transmission rate of the asymptomatic infections may be the reasons to cause the rapid spread of the recent Shanghai epidemic. It needs to implement more strict prevention and control strategies, rise the recovery rates of symptomatic and asymptomatic infections, and reduce the death rates for preventing the spread of this wave COVID-19 epidemic in Shanghai.

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Modelling, Simulations and Analysis of the First and Second COVID-19 Epidemics in Beijing

Cited by 6 publications

References 23 publications

Summaries, Analysis and Simulations of COVID-19 Epidemics in Shanghai

Summaries, Analysis and Simulations of COVID-19 Epidemics in Shanghai

Summaries, Analysis and Simulations of Recent COVID-19 Epidemics in Mainland China

Summaries, Analysis and Simulations of Recent COVID-19 Epidemic in Shanghai

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