Microbiologist here: I was taught that part of the origin of the symbol was the way a specific worm was removed, you had a stick or rod or whatever and you made a little incision where the worm is, then slowly pull it out and wind it around the rod
One of man’s first medical procedures
I’ve accepted that I will never be able to have the focus to write another campaign again because ADD, but I have a DM file with dozens of NPCs, plot hooks, and locations to add color to a campaign. Let me know if you want anything to drop in