The source has been identified as a frozen raw yellowfin tuna product labeled as Nakaochi Scrape AA or AAA.
It's not something individual consumers can buy. But it might've been used to make sushi dishes like spicy tuna at restaurants and grocery stores.
The manufacturer is recalling nearly 60,000 pounds of the product.
Of the 10 confirmed cases in Illinois, one is in McLean County and three have landed people in the hospital.