the main concern for humans from eating carefully prepared salmon raw (meaning fish caught fresh and carefully cleaned to get say a block of beautiful fillet meat) seems to be the D. Latum tapeworm, the larvae of which can be in the flesh of any fish born in moving water or those that are predators of fish harboring the larvae...the larvae cannot be seen and can be in perfect looking, right out of the water salmon fillet meat...
Bears seem to play a key role in the cycle since they will consume the fish, get infected, and the eggs in their feces get back into the water and start the cycle over again...
although the risk does appear very low, doesn't sound like much fun to get one of these things...cheers, roger