I came across some info that briefly mentioned a "ribbon worm". I didn't do enough research to determine if ribbon that what you might have, but in one of your pictures a worm does look like a ribbon!
Ribbon worm is any of a group of worms with a slender, often flattened body and a long proboscis (snout). The proboscis lies above the mouth and can be thrown out quickly and wrapped around the prey. In some ribbon worms, the proboscis has daggerlike stylets. A ribbon worm has a complete digestive tract, with openings at the mouth and anus. Ribbon worms feed on other worms and mollusks, both living and dead. They are not harmful to people.
You might want to do further research on this. I don't know if ribbon worms are white or know how large they can get, or if they can infect people but any worm can be accidental infections. The description above is rather vague.
If you find something more of interests can you post it here? Thanks :)