Hi again,
Generally people get tested to find out if they have the virus or not.
Depending on where you live in the world, will depend on what sort of treatment you will get (if any).
Of course once people know they have the virus, they can stop having sex with others without protection and can be careful about their own body fluids.
Or... they could go around having sex with others without protection and not be careful about their own body fluids, since they are already infected.