Thanks Sally.
This one reminds me a bit of my Dad telling me never to drink from mountain streams when hiking, in case I contracted liver fluke. I realise now that you'd have to be really going some to ingest a mud snail!!
The thing I find fascinating is how did these parasites evolve in the first place? For example, take the Guinea Worm. You get them by drinking water which contains an infected cyclops. Once in your stomach, the cyclops dies and releases the larvae, which burrow into your intestinal wall and then migrate into body tissue to mature and mate (yes, really!). The females then migrate to the surface of the skin, causing a blister full of larvae which bursts in contact with cool water, releasing millions of larvae..... which get eaten by a cyclops.
Like seriously? How on earth did that come about? Evolution seems to involve too many weird and wonderful steps, whilst creation involves a pretty seriously messed up God, don't you think?
Answers on a postcard please, to "Womble's parasitology and religious philosophy hour, C/O TAS".