CHICAGO (BLOOMBERG) - The concerns over the recent US outbreak of E. coli involving romaine lettuce may last no more than a few weeks, as the area of Arizona where the offending produce is believed to have come from is now out of production and California farms are taking over.
Federal officials are still trying to trace the exact origins of the outbreak that sickened more than 50 people and hospitalised 31, including five who developed kidney failure. All that's known so far is that the tainted lettuce came from near Yuma, Arizona.
The Yuma region is the US's dominant leafy-green supplier from about November through March, said Roland Fumasi, a fruit and vegetables analyst for Rabobank International in Fresno, California.
During that period, the key California growing regions are too cool or wet for lettuce production, but Arizona winters provide ideal conditions, he said.
The last legs of Yuma-area production shut down about a week ago, according to Trevor Suslow, an extension specialist for vegetables at the University of California, Davis. California's Salinas Valley is now in full swing.
Until federal officials know exactly where the offending produce came from and when its production ceased, careful consumers should stay away from romaine until about the middle of May, said Jean Halloran, director of food policy initiatives at Consumers Union, the advocacy arm of Consumer Reports.
By then, all Arizona-grown romaine will have wilted and expired on its own. Even though restaurants and retailers that received shipments from Yuma have been notified and asked to pull those products, that doesn't provide enough certainty, she said.
Romaine is the second-most popular leafy green in America. Iceberg is still the most consumed, accounting for about 55 per cent of lettuce demand, according to Rabobank's Fumasi. Romaine comes in at about 30 per cent, while other leaf lettuce is around 15 per cent.