Food

Investigation of Multistate Outbreak of E. coli O26 Infections Linked to Consumption of Raw Clover Sprouts

April 5, 2012


Final Update

April 5, 2012

According to CDC, this particular outbreak appears to be over.

A total of 29 individuals infected with the outbreak strain of E. coli O26 have been reported to CDC from 11 states. The 4 new ill persons have been reported (since the March 8, 2012 update) from Michigan, Pennsylvania, Washington, and West Virginia. Of the 27 ill persons with available information, 23 (85%) reported consuming sprouts at Jimmy John's restaurants in the 7 days preceding illness. Among the 29 ill persons, illness onset dates ranged from December 25, 2011 to March 3, 2012.

Update on Cases

March 8, 2012
Case Count Update

A total of 25 individuals infected with the outbreak strain of E. coli O26 have been reported to CDC from 8 states. The 11 new ill persons have been reported (since the February 23, 2012 update) from Alabama, Michigan, and Ohio. Of the 24 ill persons with available information, 21 (87%) reported consuming sprouts at Jimmy John's restaurants in the 7 days preceding illness. Among these 24 ill persons, illness onset dates ranged from December 25, 2011 to February 15, 2012.

February 23, 2012
Case Count Update

A total of 14 individuals infected with the outbreak strain of E. coli O26 have been reported from 6 states. The two new cases have been reported from Michigan. Both new cases reported eating at Jimmy John's restaurants and consuming sprouts in the 7 days preceding illness. Among the 14 persons for whom information is available, illness onset dates range from December 25, 2011 to February 7, 2012.

Initial Announcement

On February 15, 2012, CDC and FDA posted announcements of a multistate outbreak of (12) E. coli O26 infections reported in five states: Arkansas, Kansas, Iowa, Missouri, and Wisconsin. CDC reported illness onset dates ranging from December 25, 2011 to January 15, 2012.

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Update on FDA Investigation

February 23, 2012

  • The traceback investigation involving iceberg lettuce found no common source to link that commodity to the ongoing outbreak.
  • FDA has determined that the common seed lot identified (lot SCCTSX) was distributed nationwide.

  • On February 10, the seed supplier of the common seed lot identified agreed to notify its customers to remove the lot in question from distribution. On February 13, the supplier informed FDA that notification of all customers was complete and that instructions had been given to return any of the seed lot in question to the supplier.

  • FDA continues to monitor the removal of the seed lot in question from the supply chain.

  • Sprouts have a short shelf life (2-3 weeks).  It is unlikely that sprouts produced from the seed lot in question are currently in the marketplace.

As more information becomes available in this ongoing outbreak and the investigation by CDC, FDA and its state partners, this web page will be further updated.

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Background 

The Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and state health and agriculture authorities worked together to investigate an outbreak of 12 people with Shiga toxin-producing E. coli serogroup O26 (STEC O26) infections reported in five states: Arkansas, Kansas, Iowa, Missouri, and Wisconsin. Illness onset dates range from December 25, 2011 to January 15, 2012. Among those who became ill, there were two reported hospitalizations, no deaths, and no cases of hemolytic uremic syndrome (HUS). See CDC Investigation Announcement: Multistate Outbreak of Shiga Toxin-producing Escherichia coli O26 Infections Linked to Raw Clover Sprouts at Jimmy John's Restaurants disclaimer icon.

Preliminary results of the epidemiologic information and the traceback investigation conducted by local, state, FDA, and CDC officials indicate that eating raw clover sprouts is the likely cause of this outbreak. This is an ongoing investigation. As updated information becomes available, FDA will update this web page and/or issue other public communication.

Among the 11 ill persons with available information, CDC reports that 10 (91%) reported eating at a Jimmy John’s sandwich restaurant in the 7 days preceding illness. Ill persons reported eating at 9 different locations of Jimmy John’s restaurants in four states in the week before becoming ill. One location was identified where more than one ill person reported eating in the week prior to becoming ill. Among the 10 ill persons who reported eating at a Jimmy John's restaurant location, 8 (80%) of 10 reported eating a sandwich containing sprouts, and 9 (90%) of 10 reported eating a sandwich containing lettuce.   

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Traceback Investigation

Although FDA initially focused its traceback investigation on iceberg lettuce, tomatoes and sprouts, FDA later narrowed its focus to iceberg lettuce and sprouts because  tomatoes were considered the least likely suspect vehicle. Tomatoes have not historically been associated with E. coli contamination. CDC, state and local health and agricultural officials assisted FDA in its traceback efforts on iceberg lettuce and sprouts. The traceback involving iceberg lettuce did not result in identifying a common supplier, other common link to the restaurants where ill persons ate, or dates of illnesses. Therefore, FDA now has further narrowed its traceback investigation to sprouts. The traceback investigation did identify two separate sprouting facilities that supplied the Jimmy John’s restaurants in those states with reported illnesses. Further traceback indicated that these two sprouting facilities used the same lot of seed (lot SCCTSX) to produce clover sprouts during the time period when the illnesses occurred. Sprouts are the germinating form of seeds and are frequently eaten raw in sandwiches and salads.   In previous sprout-associated outbreaks, seeds have frequently emerged as the most likely source of contamination. 

FDA, working with its state and local partners, acted quickly to identify the source of the common seed lot sent to customers during the period when illnesses were occurring. At this time, the common seed lot is being removed from distribution and the seed supplier is currently holding all seed associated with the lot (SCCTSX) in question.

The seed supplier, distributors, and sprouting facilities are taking action to ensure that seed or sprouts associated with the common seed lot are removed from commerce in a timely manner. FDA will be monitoring these activities in cooperation with its state and local partners. FDA has collected samples of seed from the identified common seed lot in this investigation; final results are pending. 

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Clinical Features/Signs and Symptoms

Currently, there are limited public health surveillance data on the occurrence of non-O157 STECs, including STEC O26; therefore, STEC O26 infections may go undiagnosed or unreported. Because non-O157 STEC infections are more difficult to identify than STEC O157, many clinical laboratories do not test for them.

People usually get sick from Shiga toxin-producing E. coli (STEC) 2-8 days (an average of 3-4 days) after swallowing the organism. Most people affected with STEC O26 develop diarrhea (usually watery but sometimes bloody) and abdominal cramps. Some illnesses last longer and can be more severe.  Infection is usually diagnosed by testing of a stool sample. Many clinical laboratories do not test for non-O157 STEC, such as STEC O26, because it is harder to identify than STEC O157. Most people recover within a week, but, rarely, some develop a more severe infection. 

FDA Advice to Consumers

Sprouts: What You Should Know

Like any fresh produce that is consumed raw or lightly cooked, sprouts that are served on salads, wraps, sandwiches, and other foods may contain bacteria that can cause foodborne illness. Unlike other fresh produce, the warm and humid conditions seeds and beans need to sprout and grow are also ideal for the growth of bacteria, including salmonella, listeria, and E. coli. 

  • Children, older adults, pregnant women, and persons with weakened immune systems should avoid eating raw sprouts of any kind.

  • Cook sprouts thoroughly to reduce the risk of illness.

  • Persons who think they might have become ill from eating potentially contaminated sprouts should consult their health care provider.

  • Consumers can request that raw sprouts not be added to food. If you purchase a sandwich or salad at a restaurant or delicatessen, and want to avoid sprouts, check to make sure that raw sprouts have not been added.

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FDA Guidance for Industry

Page Last Updated: 08/27/2013
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