February 25, 2016
CDC is collaborating with public health officials in multiple states and the U.S. Food and Drug Administration (FDA) to investigate a multistate outbreak of Shiga toxin-producing Escherichia coli O157 (STEC O157) infections.
Public health investigators are using the PulseNet system to identify illnesses that may be part of this outbreak. PulseNet, coordinated by CDC, is the national subtyping network of public health and food regulatory agency laboratories. PulseNet performs DNA fingerprinting on STEC bacteria isolated from ill people by using techniques called pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). PulseNet manages a national database of these DNA fingerprints to identify possible outbreaks.
A total of nine people infected with the outbreak strain of STEC O157 have been reported from two states. The number of ill people identified in each state is as follows: Minnesota (7) and Wisconsin (2).
Illnesses started on dates ranging from January 17, 2016 to February 8, 2016. Ill people range in age from 17 years to 84, with a median age of 28. Sixty-six percent of ill people are female. Two ill people have been hospitalized. No one has developed hemolytic uremic syndrome, a type of kidney failure, and no deaths have been reported.
This outbreak can be illustrated with a chart showing the number of people who became ill each day. This chart is called an epidemic curve or epi curve. Illnesses that occurred after February 16, 2016 might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of 2 to 3 weeks. Please see the Timeline for Reporting Cases of E. coli O157:H7 Infection for more details.
Investigation of the Outbreak
Collaborative investigative efforts of state, local, and federal public health and regulatory officials indicate that alfalfa sprouts produced by Jack & The Green Sprouts of River Falls, Wisconsin are a likely source of this outbreak. This outbreak does not appear to be related to the ongoing multistate outbreak of Salmonella Muenchen infections linked to alfalfa sprouts produced by Sweetwater Farms of Inman, Kansas.
In interviews, ill people answered questions about the foods they ate and other exposures in the week before they became ill. Of the eight ill people who were interviewed, all eight (100%) reported eating or possibly eating alfalfa sprouts in the week before illness started.
State and local health and regulatory officials performed traceback investigations from seven different locations where ill people ate or bought alfalfa sprouts. These investigations indicated that Jack & The Green Sprouts supplied alfalfa sprouts to all seven locations.
The information available to date indicates that alfalfa sprouts produced by Jack & The Green Sprouts may be contaminated with STEC O157 and are not safe to eat. On February 24, 2016, the Minnesota Department of Health issued a press release warning consumers not to eat these products. CDC recommends that consumers do not eat and restaurants and other retailers do not sell or serve alfalfa sprouts produced by Jack & The Green Sprouts at this time.
This investigation is ongoing, and we will update the public when more information becomes available. CDC and state and local public health partners are continuing laboratory surveillance through PulseNet to identify additional ill people and to interview those people about foods they ate before they got sick.