Why can't I be a cadaver donor?

Usually, on matters like this, the rules are strictly "safety first". Remember, students will have to get elbow deep in your guts while waving scalpels around. There may well not be any risk of infection at all, but they're not taking the chance.

Hep B is a bloodborne pathogen. More importantly, its part of the hepadnaviridae family of viruses. As a virus, it is a parasite of translation. When I say translation, I mean the building of proteins in the body. A virus essentially takes over everything we use to create proteins in our body and uses them to make more viruses. But that is the key - it uses them to make MORE viruses. When a body dies, the virus may not be able to make more viruses but the ones that are already in there will stay. Sure, over time the virus will degrade and die as well but this particular virus (hep b) is extremely resistant and can survive long periods of time without replicating. So when you donate your body, you may expose other vulnerable people to hep B, even though you are dead.

+ Many people think a virus is "alive" and it is a subject of constant debate among scientists. However, the most widely agreed upon suggestion is that they are not alive (but not dead either!) because they can't create their own ATP and they can't divide. Because of this, they don't need any nutrients to survive either. The only method of survival for a virus is reproduction. So the real time of "death" occurs when a virus degrades. And sometimes, that can be years after death.