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

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. O_LIThe transmission rate of the symptomatic infections caused by the symptomatic individuals was much lower than the corresponding average transmission rate of the RMCE. C_LIO_LIThe transmission rate of the asymptomatic infections caused by the symptomatic individuals was much higher than the first 90 days average transmission rate of RMCE. C_LIO_LIThe transmission rate of the symptomatic infections caused by the asymptomatic individuals was much lower than the first 60 days average transmission rate of RMCE, and was much higher than the last 60 days average transmission rate of RMCE. C_LIO_LIThe transmission rate to the asymptomatic infections caused by the asymptomatic individuals was much higher than the corresponding average transmission rate of RMCE. C_LIO_LIThe last 30 days average blocking rate to the symptomatic infections were lower than the last 30 days average blocking rates of RMCE C_LIO_LIThe 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. C_LIO_LIThe 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 weeks recovery rate was similar to the last weeks recovery rate of RMCE. C_LIO_LIThe 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. C_LI ConclusionsThe last 30 days low blocking rates to the symptomatic infections, the first 30 days 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.

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

BackgroundGlobally 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. MethodsUsing 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. ResultsThe simulation results were in good agreement with the real word data. The recovery rates of the foreign input symptomatic and asymptomatic infected individuals are much higher than those of the mainland COVID-19 infected individuals. The blocking rates to symptomatic and asymptomatic mainland infections are lower than those of the previous epidemics in mainland China. 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. ConclusionsNeed to implement more strict prevention and control strategies to prevent the spread of the COVID-19 epidemics in mainland China. Keeping the present prevention and therapy measures to foreign input COVID-19 infections can rapidly reduce the number of foreign input infected individuals to a very low level.

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

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 epidemic 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 seven days after reaching the infection turning point until the new infection goes away.

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

Modeling and simulation are important tools that can be used to control, prevent and understand an epidemic spread. This paper introduces a symptomatic-asymptomatic-recoverer-death differential equation model (SARDDE). It presents the conditions of the asymptotical stability on the disease-free equilibrium of the SARDDE. It proposes the necessary conditions of disease spreading for the SARDDE. Based on the reported data of the first and the second COVID-19 epidemics in Beijing and simulations, it determines the parameters of the SARDDE, respectively. Numerical simulations of the SARDDE describe well the outcomes of current symptomatic and asymptomatic individuals, recovered symptomatic and asymptomatic individuals, and died individuals, respectively. The numerical simulations obtain the following results. O_LIThe transmission rate of the symptomatic infections caused by the symptomatic individuals in the second Beijing epidemic is about two times higher than the one in the first Beijing epidemic. C_LIO_LIBoth symptomatic and asymptomatic individuals cause lesser asymptomatic spread than symptomatic spread. C_LIO_LIThe blocking rates of 89.32% and 97.48% (reaching the infection turning points) to the symptomatic infections cannot prevent the spreads of first and second COVID-19 epidemics in Beijing, respectively. C_LIO_LIThat on the day 28, the symptomatic infection blocking rates reached to 100% has made the second Beijing epidemics epidemic end on day 56. C_LIO_LIThat on the day 98, the symptomatic infection blocking rates reached to 100% has made the the first Beijing epidemics epidemic end on day 140. C_LIO_LIKeeping the blocking rates, recovery rates and death rates reaching the infection turning points would make the numbers of current hospitalized infected individuals reach, on day 140, 208958 individuals and 25017 individuals for the two Beijing epidemics, respectively. C_LI Virtual simulations suggest that the strict prevention and control strategies implemented by Beijing government are effective and necessary; using the data from the beginning to the days after about two weeks after the turning points can estimate well and approximately the following outcomes of the two COVID-19 academics, respectively. To avoid multiple epidemic outbreaks, a recommendation is that the authorities need to have maintained the prevention and control measures implemented, at least, 7 days after reaching the turning point until new current infection cases disappear. It is expected that the research can provide better understanding, explaining, and dominating for epidemic spreads, prevention and control measures.

Modelling, Simulations and Analysis of the First COVID-19 Epidemic in Shanghai

To date, over 178 million people on infected with COVID-19. It causes more 3.8 millions deaths. Based on a previous symptomatic-asymptomatic-recoverer-dead differential equation model (SARDDE) and the clinic data of the first COVID-19 epidemic in Shanghai, this paper determines the parameters of SARDDE. Numerical simulations of SARDDE describe well the outcomes of current symptomatic individuals, recovered symptomatic individuals, and died individuals, respectively. The numerical simulations suggest that both symptomatic and asymptomatic individuals cause lesser asymptomatic spread than symptomatic spread; blocking rate of about 95.5% cannot prevent the spread of the COVID19 epidemic in Shanghai. The strict prevention and control strategies implemented by Shanghai government is not only very effective but also completely necessary. The numerical simulations suggest also that using the data from the beginning to the day after about 19 days at the turning point can estimate well the following outcomes of the COVID-19 academic. It is expected that the research can provide better understanding, explaining, and dominating for epidemic spreads, prevention and control measures.

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

To date, over 130 million people on infected with COVID-19. It causes more 2.8 millions deaths. This paper introduces a symptomatic-asymptomatic-recoverer-dead differential equation model (SARDDE). It gives the conditions of the asymptotical stability on the disease-free equilibrium of SARDDE. It proposes the necessary conditions of disease spreading for the SARDDE. Based on the reported data of the first and the second COVID-19 epidemics in Beijing and simulations, it determines the parameters of SARDDE, respectively. Numerical simulations of SARDDE describe well the outcomes of current symptomatic and asymptomatic individuals, recovered symptomatic and asymptomatic individuals, and died individuals, respectively. The numerical simulations suggest that both symptomatic and asymptomatic individuals cause lesser asymptomatic spread than symptomatic spread; blocking rate of about 90% cannot prevent the spread of the COVID19 epidemic in Beijing; the strict prevention and control strategies implemented by Beijing government is not only very effective but also completely necessary. The numerical simulations suggest also that using the data from the beginning to the day after about two weeks at the turning point can estimate well or approximately the following outcomes of the two COVID-19 academics, respectively. It is expected that the research can provide better understanding, explaining, and dominating for epidemic spreads, prevention and control measures.