Most people on here prefer humaworm. To kill parasites outside of the intestines a zapper is recommended.

This website gives an overview of parasites.
10 human parasites | internal human parasites | human tape worm
As a result it is a marvelous environment for a few sometimes nasty internal human parasites. Trematodes such as the Chinese liver fluke, Clonorchis sinensis is one such animal.

essential-parasite-resources.com/human_parasites.html