Doctors scoff, but Americans may have as many parasites as people in third-world countries do. Sequelae can be neurological, as parasites rob us of needed nutrients, and once in the body, can go to the brain.
Read a discussion of health care and parasites at Democratic Underground and marvel at America's lack of health care and the billions going towards swine flu while nothing is done about parasites.
You may also find this information of interest.
From truth to fiction....
Colin Wilson's sci fi/horror novel THE MIND PARASITES thrilled us years ago, and we're delighted by this great review: http://realitystudio.org/texts/reviews/mind-parasites/
Wilson's parasites seem to be the sinister love child of
Dow's Scrubbing bubbles... and Cthulu.