Why did you receive a visit or pass through the risk area after two consecutive nucleic acid tests, and you haven't been out recently?

This area is a dangerous area. Nucleic acid detection is to detect whether the pathogen is infected. It has been tested twice in a row, and it hasn't happened recently. It is because the region belongs to the risk area that nucleic acid should be made. High-risk areas refer to the residences of cases and asymptomatic infected persons, as well as workplaces and activities with frequent activities and high risk of epidemic spread.