Health issues

Pigs can harbour a range of parasites and diseases that can be transmitted to humans. These include trichinosis, Taenia solium, cysticercosis, and brucellosis.

Pig t shirts are also known to host large concentrations of parasitic ascarid worms in their digestive tract. The presence of these diseases and parasites is one reason pork meat should always be well cooked or cured before eating. Today, trichinellosis infections from eating pork are relatively uncommon, at least in the United States, due to more stringent health laws, better refrigeration, and public awareness of the dangers of eating undercooked meat. Some religious groups that consider pork unclean refer to these issues as support for their views.

http://en.wikipedia.org/wiki/Pig