Asymptomatic infections are generally not contagious when they turn negative.
Asymptomatic infected persons are those infected with the relevant pathogenic bacteria, but without any clinical manifestations, belonging to the hidden infection, but can be diagnosed through nucleic acid testing and other pathogenic bacteria testing, after effective isolation after multiple checks of nucleic acid and so on are negative, often suggesting that it is not contagious.
The current global epidemic is still unstable, and there are more asymptomatic infected people, if they are asymptomatic infected people need to be effectively controlled according to the local policy, to avoid causing the spread of pathogenic bacteria, good hand hygiene, wear a good mask.
Usually to exercise more to improve their immunity, if multiple tests are negative, the isolation period has reached more than two weeks, you can lift the isolation, generally not infectious.