Being a Microbiology buff of a few decades back - I make it a point that all meat be cooked well done. So far as I know there are no microbes or parasites that will survive a temperature of 265 degrees Farenheit. Obviously, this is far above boiling at 212 degrees Farenheit. Some microbes can withstand boiling.
Beef tape worm - Cysticerci are ingested from rare or undercooked meat. The tapeworm attaches to mucosa of the small intestine. New segments are formed behind the attached head and old segments break off of the tail, which makes the expelled feces of the host infectuous because of the eggs contained in the dispelled segments.
Guinea worm - (Country of Ghana) lives in the body of the host and may be up to three feet in length. Worms break through the skin and exit the body. An incision is made in front of the path of a worm, if it is visible, and it is pulled out gently by winding it on a stick. If it breaks off and recedes, it often pulls in Tetanus spores, which eventually kills the host. The practice in some parts of the world is to treat the wound with cow dung, which is a source of Tetanus. These worm parasites have been known to pass through the eyes of the host. The source of this worm is contaminated water. A couple decades ago about 10,000,000 people were infected with the Guinea worm. There is no cure - only prevention.
And there are many many more parasites in the books. One causes elephantiasis, which is a horrible deforming disease caused by a roundworm parasite. Fortunately, we do not live in an environment where these parasites propagate, but we do have some. We have processed and chlorinated water and our houses are kept very clean. We wear shoes all of the time, but our point of vulnerability is via our food, which can be contaminated by parasites and microbes. Here we need to be on our guard.