Termination criteria: high-risk area: no new infection for 7 consecutive days. On the 7th day, all personnel in the risk area were negative for nucleic acid screening, and changed to medium-risk area; For three consecutive days, there was no new infection, and then it was reduced to low-risk areas.
Medium-risk area: there was no new infection for 7 consecutive days. On the 7th day, all the people in the risk area were negative for nucleic acid screening, and they were changed to low-risk areas.
Low-risk area: there is no middle-high risk area in counties (districts, cities and banners), and the low-risk area is adjusted to normal prevention and control.