Usually people can contract roundworms. Just use common sense. Wash
your hands after handling the litterboxes and the ferrets. The only way
to catch roundworms is if you ingest/eat the eggs. As you can imagine,
most people don't go eat a sandwich or prepare food directly after
cleaning litterboxes or handling animals, so you should be safe. It is
usually children who end up catching roundworms from their puppies who
contract these pests.
As for earmites, you are safe from ferret earmites. However, there
are other kinds of mites that are known to infest human ears, but
not these.
Laryssa
[Posted in FML 6098]