Flukes and nematodes are very easy to detect. Eating raw tuna IS safe unless you get it from a very bad source. Fish markets that catch the tuna from the ocean and sell it for sashimi should not be a problem and it's rather cheap as well. I buy my tuna ate $3-$7 a pound. Sushi bars is another great source but are usually very expensive and they tend to sometimes freeze the fish before serving (which diminishes the quality of the fish). If you get it farm/factory-raised, that's when I would worry about eating anything RAW. Always know where your food is coming from!
I don't know what reports you're talking about, but here's something i've read: "Annually, less than 40 US citizens get ill by consuming fish containing parasites. In comparison: Every year thousands are bitten by snake." Hmm... Imagine that!
Another thing I have found -- According to mednets.com, there has only been ONE case ever of someone who had absorbed nematodes from sashimi.
You have to know the type of fish that you can eat raw and those to avoid. Tuna is great and safe to eat raw!
You say, there is a very high incidence of that infection when compared to other population? Is this the same population that makes it a lifestyle at eating worm & maggot-filled, Antibiotic stuffed chicken? I think the population may need a parasite cleanse more than the dedicate raw foodist.