Did you keep yourself slathered 24/7, like right after having a bowel movement? Have you removed any other possible sources of contamination, or maybe bleached any?
Do you work with, or live with, small children? If you live with any, they probably need to be treated also. Diatomaceous earth, food grade, might get rid of them, also, 1 heaping tbsp per day preferably first thing in the morning w/no food for 1/2 hour, except maybe some juice.