If you maintain a clean alkaline, oxidised body to start with, parasites and such things cannot survive within you period.
so no need to worry even about that aspect.
avoiding dead foods, canned produce etc, foods that build up toxins,
and create an environment that allows such things to thrive within
would/should be a natural goal of any healthy minded person.
so many foods, spices and herbs are very antiparasite/antibacterial,
to include these every day in your eating intake would certainly help,
as well as maintaining good waste system alkalinity through,
colon cleansings and oxidisations.
A very good simply means is thru use of products such as Colosan..
and of course Liver Flushes etc..
and paying attention to what you ingest and even cook on.