What is the basis of CDC calling to confirm the secret contact?

Epidemiological investigation professionals are based on epidemiological investigation results and big data information provided by relevant departments.

People who are in close contact with suspected cases and confirmed cases but have not taken effective protection since 5 days before symptoms appear, or 5 days before sampling asymptomatic infected people. According to the epidemiological investigation results and big data information provided by relevant departments, epidemiological investigation professionals determine close contacts according to the following principles:

1, family members sharing a room;

2. Direct caregivers or providers of medical and nursing services;

3. Medical personnel who may carry out aerosol diagnosis and treatment activities in the same space;

4, in the office, workshop, team, elevator, canteen, classroom and other places with close contact with people;

5. * * Dine in a closed environment, * * provide entertainment and catering entertainment services;

6, medical personnel, family members or other close contact with the visit;

7. People who take the same vehicle and have close contact, including caregivers and colleagues (family, colleagues, friends, etc.). ) on the vehicle;

8. Persons exposed to the environment and articles contaminated by cases or asymptomatic infected persons;

9. On-site investigators evaluate other personnel who meet the criteria for judging close contacts.