The Talmud says:
One who injures another becomes liable for five things: damages, pain, medical expenses, incapacitation, and mental anguish. [Bava Kamma 83b]
It does not spell out HOW or WHY the injury was inflicted. This brings me to my question:
If you have a potentially deadly contagious disease, are you liable under Jewish law for coming close to another person and infecting him with it?
We probably have to consider three cases:
(1) You know you are infected, but, because of necessity or other, less compelling, reasons, you come close. (Are you obligated because of pikuach nefesh to isolate yourself?)
(2) You don't know you are infected, but know there is an epidemic and know that many infected people do not show any symptoms. Secular authorities enjoin you to stay away from others, but it is not a law and is not enforced, so dina de-malchuta dina does not apply.
(3) You don't know you are infected and there is no epidemic or awareness of a problem.