Sorry to sound like are know all, its what I've been told
I spent some time in the outback, and was told that pigs can carry a desease, called something like sparagonis, it is a tape worm, and is similiar to a desease found in dogs, and can be passed on to humans, it usually goes in a persons brain
Talked about it with a friend who came from Iran, he said that the desease is rampant in the middle east. So my guess is that some Prophit, saw that eating pork was causing serious health problems, and baned his people from eating it, The jews probably saw the same thing and baned it to.
A ranger told me that the desease is very rear in Australia, and only traces have been found in Northern Tropical Australia. He said that it is safe to eat wild pork even up North if it is well cooked