Parasites, by their very nature, are deceptive. They can “trick” the immune system into thinking, sometimes, though they are part of the normal scenery.

When I was in practice, I noticed a peculiar thing about parasites.

I would say that about 4 or 5 times during the years that I was practicing, the subconscious mind of the patient would give me an answer that there were no parasites in the body. However, I had a strong suspicion that there actually were parasites inhabiting the body, so I was left to puzzle over why the subconscious mind would give me this "no" answer, and whether or not this was correct. 

On a hunch, the first time this happened to me, I tested the patient to see if they needed any of the parasite formulas. They did! Strange, eh?

It seemed that, the longer the parasites had been in the body, the less likely it was that the body would “recognize” them. Or, this may be a phenomenon that happens more easily with certain types of parasites, I don't know. And granted, this is not a very common finding, but it does occur.