More than two months later, one person is dead in California, 75 others have been hospitalized, and federal authorities still don't know where a nasty strain of E. coli bacteria latched onto romaine lettuce from Yuma, Ariz.
Their struggle to trace dozens of supply lines across 32 states, on a paper trail that often may actually be on paper, demonstrates the limits of tracing food by methods rooted in another century.
Food safety advocates and industry insiders say it may be time to borrow the encrypted accounting platform that drives cryptocurrency: blockchain.
"I often describe that as food traceability at the speed of thought — as quickly as you can think it, we can know it," said Frank Yiannas, vice president of food safety for Walmart, which is scaling up an IBM-driven pilot blockchain that already includes top suppliers such as Unilever, Nestle and Danone.
