Covid-19, March 7th, the reporter learned from the news conference of the new crown pneumonia prevention and control work in Xi’an (sixty-third). The virus that caused the local epidemic in Xi’an is a BA2 subtype of the gene. The mutation of the virus has many spots, short latent period, strong infectivity and fast propagation speed. From 0:00 to 9:00 on March 7, Xi’an added four locally confirmed cases. Although they are close contacts of previously confirmed cases, there have been third-generation cases, which fully shows the rapid spread of the virus. Moreover, the transmission of Ba2 subtype in Omicron virus strain is more concealed than that of BA1 subtype, the symptoms are not obvious, and the transmission speed is also increased by 30%. This series of characteristics show that the virus is more likely to cause multi-point sporadic or concentrated outbreaks.

According to the current epidemiological investigation results, the epidemic situation in Xi’an is in the early stage of discovery, and the source of the epidemic situation is clear. However, due to the complex activity track of many infected people, involving schools, public transport, restaurants, hotels, hospitals, shopping malls and other crowded places, there is still a great risk of community transmission and spillover, In order to implement the four early measures of “early prevention, early detection, early reporting and early isolation”, it is necessary to carry out in-depth and detailed investigation of risk personnel, carry out nucleic acid screening in a large range, find possible sources of infection as soon as possible, find and block the transmission of virus, and protect the health of citizens.