introduction
an unknown new human coronavirus, now termed coronavirus disease 2019 (covid-19), was identified in december 2019 in the chinese city of wuhan. following the spring festival in china, suspected cases appeared in other regions of china and other countries, and the numberof confirmed patients increased rapidly. at the end of january 2020,the world health organization (who) listed this outbreak of covid-19as a public health emergency of international concern [2]. although the virus was first discovered in wuhan, the original source of the virus is still undetermined. recent traceability studies have confirmed that the virus has appeared in some western countries before the wuhan outbreak. due to the exponential nature of the transmission, who declared covid-19 a global pandemic on march 11, 2020. as of may 5, 2021, more than 150 million confirmed cases had been reported worldwide, covering almost all countries, including the united states, india, brazil, france, turkey, russia, the united kingdom, italy, and spain, among others.
methods
data collection
model procedure
results
epidemic progression and net-seaihrq model prediction for mainland china
epidemiological parameter estimates
comparison of effects of different prevention and control measures
intervention intensities of various provinces in mainland china
discussion
although the covid-19 epidemic in china has been brought under control, the virus is still spreading widely across other parts of the world.the results of this study show that if the very proactive and aggressive containing measures that had been implemented had not been taken by all 31 provinces in china, approximately 3.08% of the chinese population (43 million) would have been diagnosed with covid-19 by april 30, 2020. unlike some countries that hesitated to declare a state of emergency until the epidemic became severe for fear of possible economic interruption, many provincial governments in china chose to take the risk of detrimental economic effects to impede the rapid spread of the epidemic. in addition to the very proactive and aggressive measure of declaring the first-level emergency at a very early stage, many provinces quickly followed up by implementing all effective measures taken by the leading provinces. to the best of our knowledge, this study is the first to include an analysis of the intervention effects and intensity of covid-19 epidemic control measures in various provinces in china based on the net-seaihrq model.
conclusion
the proposed net-seaihrq dynamics model fit the data from the various provinces well in terms of the number of confirmed cases. we predicted that if no measures had been taken, 3.08% of the population of china would have been diagnosed with covid-19 by the end of april 2020, and more than 95% of the people would have become infected.the simulation results from different models showed that strict social distancing is the most effective method of prevention and control, and this measure in conjunction with isolation and traffic control can effectively reduce additional covid-19 cases before a vaccine is developed. in china, guangdong province exhibited the best prevention and control effect, and shanghai implemented the most intense social distancing measures and measures to isolate close contacts. in the context of the global covid-19 pandemic, the prevention and control experiences in these key areas can provide valuable reference information for outbreak areas.
