I'm not totally on board with this.

Hmmm.
This may be offensive to some....not meant to be
Given that pig valves and other parts may be used as replacements for humans, makes me wonder why historically some religions/beliefs consider pork unclean(inedible)?

Are pork and human flesh/organs similar? Makes one wonder................ Just saying,
I would love to answer that, but that would break the OPs "no religious talk" request

So, let me say this, get your hands on a book called "none of these diseases" and you will find the Christian-Judeo answer to that questions

On a side note...do you ever watch a show called "monsters inside of me"?

Out of all the transmission possibilities for parasites, the main one seems to be undercooked pork