Interesting that you say giardia AND cyclospora. So far, I have identified cyclospora, cryptosporidium, iodamoeba butschlii, and blastocystis hominis. I suspect that one of these protozoa is giardia, but I have not seen the distinct flagellum which makes the confirmation. It is definitely part of the same family, or could be a mutation, since they are no longer motile [because of attachment] The main thing is, that I am aware of the fact these creatures do cause chronic ailments.
My next step to to try an isolate ang grow them in vitro, so I have a better chance at studying vulnerabilities to their survival. My opinion right now, is that these will be permanent without some chemical, or surgical intervention. Shroom