Summaries, Analysis and Simulations of Recent COVID-19 Epidemic in Mainland China During December 31 2021-December 6 2022 (preprint)

Background: The recent COVID-19 epidemic in mainland China is an important issue for studying the prevention and disease control measures and the spread of the COVID-19 epidemic. Following our previous study for the mainland China epidemic during December 6 2021 to 30 April 2021, this paper studies and compares the the mainland China epidemic during December 6 2021 to December 6, 2022. Methods: Using differential equations and real word data (both domestic and foreign input infected individuals) modelings and simulates COVID-19 epidemic in mainland China during May 1 2021 to December 6 2022, estimates the transmission rates, the recovery rates, and the blocking rates to the symptomatic and the asymptomatic infections. Results: The simulation results were in good agreement with the real word data. (1) The average input transmission rate of the foreign input symptomatic infection individuals was much lower than the average transmission rate of the symptomatic infection causing by the mainland symptomatic individuals. (2) The average input transmission rate of the foreign input asymptomatic infection individuals was was much lower than the average transmission rate of the asymptomatic infection causing by the mainland symptomatic individuals (3) The average recovery rates of the foreign input COVID-19 symptomatic and asymptomatic infected individuals were much higher than the average recovery rates of the mainland COVID-19 symptomatic and asymptomatic infected ndividuals, respectively. For the mainland epidemic simulations: (1) If kept the transmission rates, the recovery rates, the death rate and the blocking rates on day 181 (June 30, 2022), the numbers of the current symptomatic and asymptomatic individuals would reduce to about one on day 277 (October 4, 2022). (2) If kept the transmission rates, the recovery rates, the death rate and the blocking rates on day 340 (December 6, 2022) until day 377 (January 16, 2023), the numbers of the current symptomatic and the asymptomatic infected individuals would increase to 38896 and 230924, respectively, the cumulative death individuals would increase from 599 to 615, respectively. (3) If kept the transmission rates, the recovery rates on day 340, but decreased the blocking rates to 30% and select the death rate to equal to the average death rate during days 104-150, then the simulation showed that on day 377, the numbers of current symptomatic and the asymptomatic infected individuals would increase to about 33 723 8057 and 501 626 885, espectively, and the cumulative death individuals would reach about 1 012 543. For the foreign input epidemic simulations: (1) If kept the transmission rates, the recovery rates, and the blocking rates day 242 (August 30, 2022), until day 340, the numbers of the current symptomatic and the asymptomatic infected individuals would decrease to 13 and 430, respectively. (2) If kept the transmission rates, the recovery rates, the death rate and the blocking rates on day 340 until day 377 (January 16,2023), the numbers of the current symptomatic and the asymptomatic infected individuals would decrease and increase to 185 and 1935,respectively. (3) Recommendations on COVID-19 epidemic base on WHO's technic guidelines and HBV Infection in Chimpanzees are provided. Conclusions: (1) For the mainland individuals' epidemic, keeping the blocking rates of over 86% and 93% to the symptomatic and asymptomatic infections , and the recovery rates of over 0.119 and 0.112 to the symptomatic and asymptomatic individuals may make the numbers of the current symptomatic and asymptomatic infected individuals to decrease to very low levels in three months. (2) For the foreign input individuals' epidemic, keeping the transmission rates of under 0.07 to the symptomatic and asymptomatic infections , and the recovery rates of over 0.125 and 0.099 to the symptomatic and asymptomatic individuals may make the numbers of the current symptomatic and asymptomatic infected individuals to decrease to very low levels in four months. (3) After December 6, 2022, decreasing the blocking rates of under 30% to the symptomatic and asymptomatic infections may cause over 800 millions individuals' COVID-19 infections and over 10 millions COVID-19 infected individuals' death. (4) It is necessary that administrations implement strict prevent and control strategies to prevent the spread of new COVID-19 variants.

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

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 (preprint)

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 172022. 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.

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

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.

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

To date, over 182 million people on infected with COVID-19. It causes more 3.9 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; the blocking rates of about 80% and 97.5% to the symptomatic individuals cannot prevent the spread of the first and second COVID19 epidemics in Beijing, respectively. Virtual simulations suggest that the strict prevention and control strategies implemented by Beijing government are 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 14 -- 17 days at the turning point can estimate well 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.

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

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 (preprint)

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 forepidemic spreads, prevention and control measures.