I did a lot of research about this as I was also craving it, and most sushi is absolutely fine, even raw sushi, this is because just about all sushi that you can get in shops and restaurants has been frozen for at least 24 hours, this is in order to kill parasites that are what carries the risk. There is a lot of contradictory information on the internet though, so if in doubt, don't eat it or ask to make sure that it has been deep frozen. But after doing my research, I was happy to eat sushi based on recommendations from medical websites.