I had a similar experience and I'm from Canada - Toronto. 19yrs ago i went home with a worm in my foot. It started itching on the plane. My son had me show all the kids at the daycare , he was 4. They loved the worm, however i did not, it was very itchy. I visited my GP,she prescribed a cream, i applied it , worm gone in a matter of days, much to the dismay of my son's daycare pals. I'm not sure why you have had such difficulty. I do know that mine was contracted via a mosquito bite and dirty floors in the cabin i stayed at.