1. Cell phone signal According to your roaming record, it is found that you have been active or passed through the "danger zone".
2. The train number you took, the flight you took and the community you lived in detected this case.
3./kloc-people with abnormal data within 0/4 days.
4. Isolation is less than 14 days.
5. The hospital has a "bad record". The function of health code is to let employees check their health status. Recently, with the aggravation of the epidemic, the epidemic prevention and control reached a climax. In order to prevent floating population from being infected, health code plays a very good role, and we can also see our personal status in every trip in different places in our lives.