Trichinosis is caused by a parasite sometimes found in pork, although most pork in the United States no longer contains this parasite, according to an article on the Epicurious.com. The Centers for Disease Control and Prevention report only 90 cases between 2008 and 2012, compared to 400 cases per year in the 1940s.
https://healthyeating.sfgate.com/consequences-eating-rare-meat-10828.html