I have experienced that partaking of some south-of-the border nasty variety (probably laced with lots of pesticides and stepped on hard with god know's what else) seemed to precede the appearance of horrific parasite symptoms! This does not mean the nasty weed introduced parasites that were never there before - NO, there were some on board already I'm sure, but I introduced into sinus and lungs some Really bad new stuff that I am still trying to get rid of years later - Beware! And it created a vicious cycle of need - the need to subdue the parasite presence with more of the nasty weed - so I was stoned and the parasites were too, for two long years and boy when I snapped out of it I had a LOT of work to do.......