Revealing the influence of national public health policies for the outbreak of the SARS-CoV-2 epidemic in Wuhan, China through status dynamic modeling

tianyi qiu; Han Xiao

The epidemic of SARS-CoV-2 has spread to China and multiple continents, which will be developed into a worldwide epidemic. During the epidemic period, nowcasting and forecasting are crucial for public health planning and control domestically and internationally 12, 22 . Here, we constructed a real-time status dynamic SEIO (MH) model to estimate the local outbreaks. By adding the parameters of status M and H, this model could accurately forecast the epidemics when the medical system under unexpected pressure. Moreover, this model could simulate the influence of different public health policies such as 1) lockdown of the city and 2) construction of temporary hospitals, which could help design the appropriate public health policies for epidemic control. At present, besides Wuhan, the epidemic situation in China has been effectively contained within a short period of time. This is largely due to the rapid response of the Chinese governments at various levels and the decision to lock down Wuhan, which is the first time to block a city with over 9 million permanent residents in human history. The lockdown of Wuhan would not only prevent the transportation between Wuhan to other cities, but also decrease the circulation intensity of people within Wuhan. According to BAIDU migration data, the circulation index of Wuhan is 6 to 8 times lower than those before the lockdown. The number of newly confirmed cases increased rapidly after the lockdown may due to the fact that, there have been already 4,521 infected and 6,536 exposed without symptoms before lockdown. It is noted that only 444 confirmed cases were reported by the Health Commission of Hubei Province 16 . However, by facing an epidemic with the new pathogen, it is difficult to invent the diagnosis kit in such a short time. Thus, the diagnosis quantity might affect the early understanding of the epidemics and the lockdown decision at that time was decisive and timely. In fact, even one day delay of the lockdown would make 17,631 more infected people at the end point and a one-week delay would make the epidemic in Wuhan uncontrollable with over 1.9 million infectious.