I am not sure how rare it is and I have not traveled to other countries. I do know that you are not correct with the hospital labs being able to identify through stool tests, as I had 2 tests done, because I told them I seen a live one. The tests did not reveal anything and the gastro doc told me it was a piece of fiber which will seem to move. Well, I did get my doctor to prescribe me prazi and after that I was able to find more "dead" flukes. The lab tests were worthless! A endoscopy and colonoscopy the same week was worthless with this matter as well.
I don't know how I got it or how common it really is.....a mystery to me. I am continuing with clarke's double strength tincture since I finished the 3 day course of prazi.