"A sushi chef's hands are always clean," Kazutoshi Endo, the head sushi chef of London's Zuma, once told me during dinner at an izakaya (pub). This comment came after he suddenly used his fingers to place a piece of fishcake on my plate, in lieu of chopsticks. It elicited a round of guffaws at our table, and the chef hastened to clarify himself.

"Seriously, I spent my first year as a sushi chef in Japan doing nothing but cleaning," he said, presenting his immaculate palms as evidence. "In the sushi world, hygiene is everything."

Hygiene was the word of the day at the inaugural Global Sushi Challenge, which took place in Tokyo on Nov. 25. In a brightly lit room inside of the Tokyo Marriot Hotel, contestants from 14 regions in Asia, Europe and North America vied for the title of champion as judges from the World Sushi Skills Institute (WSSI) rated them on cleanliness, organization and technique. Lapses of hygiene, such as cutting a finger or failing to wipe work surfaces, were penalized severely. The contest, sponsored by the WSSI and the Norwegian Seafood Council, was established to increase the knowledge and skills of sushi chefs around the world. According to the event organizers, the number of sushi restaurants abroad has risen to an estimated 20,000, but most are run by staff with insufficient training in food safety and sushi basics.