How can you be sure, you are not ingesting invisible parasites or their eggs with the raw fish? I saw that happen on reality TV show “monsters inside me”.
I can't be sure, any more than I can be sure that I won't be killed by a drunk driver on my way to work.
Neither risk is high enough to make me modify my daily activity.
“... you are not ingesting invisible parasites or their eggs with the raw fish?”
Saltwater fish, especially deep-water fish, are quite safe. Avoid estuary, near-shore, or freshwater fish, and don’t eat raw crab or other shellfish unless you know where they’re from. Lung flukes from Chinese raw crab are still a problem (as are tapeworms and other worms from beef, pork and water buffalo in much of Asia). I will eat most oysters raw, but I don’t eat Chesapeake oysters unless they’re cooked. Same goes for imported shrimp, especially ones from SE Asian shrimp farms.