I believe you can argue that she was violating people's rights. You're responsible for your properties. If your dog escapes and hurt the neighbor's son, you're responsible. If your car loses its breaks all of the sudden, while parked, and end up running over some one, you're still responsible, even if you were not driving it. If your factory or nuclear plant leaks pollution and hurt people living nearby, you're responsible. And so on.
Mary was responsible for her body. Her body was the transporting a lethal disease. She could be deemed responsible.
I feel that I [dis]agree that a disease in you body is your own property since it is an invader. A guy trespassing in my house might kill a guest there, but I don't think that I'm responsible. It would be different if Mary intentionally infected herself to then go on and intentionally infect others, but in this case she didn't even know.
That analogy is not accurate. It would be more like a guest in your house (Mary's immune system had ceased fighting the disease, effectively coming to a truce) used a sniper rifle to kill people in your neighborhood. It's his doing, but if you let him stay, it's your fault if he keeps killing.