/kloc-people who may have been exposed to confirmed cases or asymptomatic infections within 0/4 days (time-space partners). With the help of big data judgment, people or asymptomatic infected people in a certain range around the activity track of confirmed cases were judged as time-space companions, and health monitoring was carried out for 7 days after the code was assigned, and * * * nucleic acid was detected for 3 times on 1, 3 and 7 days. People who have lived in cities and counties where high-risk areas are located or potential communities to spread risks.
Have been to a prefecture-level city (state) where there are high-risk areas; Or the prefecture-level city (state) in this jurisdiction has a report of confirmed infection within 14 days, in which 1 or above infected people had a history of community activities before being found, but were not found in the isolated control population.