Maybe the worms get them first.
source: http://www.straightdope.com/classics/a2_060.html
this sounds suspiciously close to an X-Files episode… (The Host, 2nd Season, episode 2.02) … Anyone know if this story is the source for the episode, the otherway around or jest blind coincidence? Also, for future Updated Cecil Classic’s… how about putting the date of the update… this Classic was originally done in '85… but we have no way of knowing when these updates were added…
That was one of the freakiest X-files episodes… I remember it well. But the worm in question there was a Flukeworm, a trematode. Here is a photo of a fluke. Fluke infections are generally contracted by drinking or inadvertently swallowing water contaminated with trematode eggs.
In comparison, the sushi worms are nematodes, usually contracted by eating the raw flesh of infected fish.
I recommend the crab roll, or the shrimp tempura roll on your next visit to the sushi bar. Even a Dragon roll. If you really must have raw fish, I recommend the salmon, if it’s fresh.
Naw, I’ll stick to fish that was safely frozen 
As for condiments, what’s commonly called wasabi in North America is really horseradish dyed green. The real stuff is prohibitively expensive and difficult to grow.
In his column, Cecil also added ceviche to the list and I thought that was odd because even though ceviche isn’t cooked by heat it is cooked by the acid in the lime juice. How does this equal raw fish/seafood?
Wouldn’t something like ceviche be considered cooked?
Ceviche is not considered “raw” since the acids in the lemon or lime juices typically used for the marinade denature and crosslink the proteins of the flesh much as heat does during cooking. Thus, the fish in ceviche is firm and more easily digested, just as if it had been cooked over heat. (I personally prefer shrimp ceviche over fish, but the chemistry is the same.)
However, many living parasitic organisms or their eggs, should they be present, are hardy enough to survive exposure to the acids, and are therefore not killed… much less denatured.
More info on ceviche here, along with several salivation-inducing recipes.
True… Dragon physiology probably isn’t very conducive to parasite growth, and depending on the variety, the flesh may even be pre-cooked or pre-pickled.