A total of 14 people have been infected with the outbreak strain of E. coli O26 from 6 states in the fifth outbreak involving sprouts served on Jimmy John’s sandwiches in the past four years

The U.S. Centers for Disease Control report the number of ill persons identified in each state is as follows: Iowa (5), Missouri (3), Kansas (2), Michigan (2), Arkansas (1), and Wisconsin (1).

Two ill persons have been hospitalized, and no deaths have been reported.

Preliminary results of the epidemiologic and traceback investigations indicate eating raw clover sprouts at Jimmy John’s restaurants is the likely cause of this outbreak. Preliminary traceback information has identified a common lot of clover seeds used to grow clover sprouts served at Jimmy John’s restaurant locations where ill persons ate. FDA and states conducted a traceback that identified two separate sprouting facilities; both used the same lot of seed to grow clover sprouts served at these Jimmy John’s restaurant locations. On February 10, 2012, the seed supplier initiated notification of sprouting facilities that received this lot of clover seed to stop using it. Investigations are ongoing to identify other locations that may have sold clover sprouts grown from this seed lot.

Based on previous outbreaks associated with sprouts, investigation findings have demonstrated that sprout seeds might become contaminated in several ways. They could be grown with contaminated water or improperly composted manure fertilizer. They could be contaminated with feces from domestic or wild animals, or with runoff from animal production facilities, or by improperly cleaned growing or processing equipment. Seeds also might become contaminated during harvesting, distribution, or storage. Many clover seeds are produced for agricultural use, so they might not be processed, handled, and stored as human food would. Conditions suitable for sprouting the seed also permit bacteria that might be present on seeds to grow and multiply rapidly.

Earlier this week, William Keene, senior epidemiologist at Oregon Public Health Services, told The Packer that problems with sprouts originate with how they’re produced.

“It’s a generic problem, not a this-guy-was-doing-something-wrong problem. The conditions for generating sprouts commercially are almost like designing a process to grow bacteria. It’s wet, it’s not too cold. The sprouts grow luxuriantly and so do the bacteria.”

Trevor Suslow, an extension research specialist at the University of California-Davis, said it’s critical for regulators, industry representatives and academics drafting the FDA rule on sprouts to address seeds.

“I am not sure it will include seed production. Based on an outline, they were starting at the seed distributor, which is not adequate to protect the public. I hope they’ll put this back in….It appears to be very difficult to keep seed that has some low level of contamination from being introduced into the sprout production stream.”