@zinfamous can you explain this for me. I believe it relates to your job.
I saw a discovery TV show a long time ago, I forgot most of the show but I remember one part about most viruses originate in China because chickens & pigs live in close proximity to each other.
*I think* it went, chickens feed where cows poop, they get sick from some cow virus that mutates in the chicken, chickens then poop near the pigs which mutates the virus more, chickens eat near pig poop and now the virus has mutated enough to be contagious to humans.
Something about each step made infecting the next animal possible. Sort of remember hearing if China just farmed like nearly anywhere else in the world and kept chickens separated from pigs we would have far fewer viruses.
I think the mutating in a pig made it possible to reinfect birds and also made it possible to infect humans after the birds.
Sorry for being so vague and my order is likely messed up.