Even though opossums seem to be cute creatures, they can be carriers of different diseases that can be harmful to humans. For example, they are known to carry leptospirosis that can become the cause of death of some humans. They are also carriers of tuberculosis which can make people uncomfortable. A lot of the opossums live in the wild and are sometimes carriers of ticks and fleas that may transfer to some house pets.
Take note that they can be harmful to humans only if they attack. They also have the tendency to attack pets when they are threatened. It is best to leave them alone so that the diseases they carry will not transfer anywhere else.