A multistate outbreak of Shiga toxin-producing E. coli and Salmonella infections linked to alfalfa sprouts has renewed attention on a class of bacteria that, despite decades of regulatory reform and scientific advancement, continues to cause severe illness and, in some cases, life-threatening complications across the United States. The outbreak, traced to alfalfa sprouts produced by Everything Sprouts of Minnesota and sold under the Calco and Everything Sprouts brands, has sickened at least 55 people across 15 states, with four hospitalizations reported as of September 15, 2026.
Outbreak Overview
According to the U.S. Food & Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC), the outbreak involves multiple serotypes of Shiga toxin-producing E. coli, including O26:H11, O103:H25, and O168:H8, along with Salmonella Agona. Of the 55 confirmed cases, 46 individuals were infected with Shiga toxin-producing E. coli (STEC), seven with Salmonella, and two with both pathogens simultaneously. Illnesses began between May 31 and August 8, 2026. The affected states include Florida, Indiana, Iowa, Kansas, Michigan, Minnesota, New Hampshire, New York, North Carolina, North Dakota, Pennsylvania, South Carolina, South Dakota, Washington, and Wisconsin.
The Minnesota Department of Health reported 23 state residents became ill between July 8 and August 8, with two hospitalizations and no deaths. Wisconsin identified 18 cases. Of 34 people interviewed by public health officials, 26 reported eating alfalfa sprouts, a significant statistical association given that only 8.7% of respondents in the FoodNet Population Survey reported eating any sprouts.
Everything Sprouts, LLC recalled certain lots of alfalfa sprouts and sprout-mix products on August 21, 2026. Recalled products were packaged in 5-ounce plastic containers with lot numbers 222, 223, 225, 226, and 230. The same alfalfa sprouts were used in Everything Sprouts Crunchy Protein Sprout Mix and Zesty Garlic Mix cups. The recalled products were distributed to wholesale distributors and grocery stores in Minnesota and Wisconsin from May 27 to August 21, 2026. On August 29, the company expanded the recall to include Robust Radish Mix distributed from August 13 to August 26, 2026.
Understanding STEC and Its Mechanisms
Shiga toxin-producing E. coli are strains of the bacterium Escherichia coli that produce Shiga toxins, potent cytotoxins that damage the lining of the intestine and, in severe cases, the kidneys and other organs. The most commonly identified STEC serotype in the United States is O157:H7, though non-O157 serotypes, including O26, O103, O111, O121, and O145, are increasingly recognized as causes of outbreaks.
STEC is transmitted primarily through the fecal-oral route. Infection occurs when a person ingests food or water contaminated with microscopic amounts of feces from infected animals or humans. Common vehicles include undercooked ground beef, raw milk, unpasteurized juices, contaminated produce, including leafy greens and sprouts, and contaminated water. Person-to-person transmission can also occur, particularly in daycare settings and among household contacts, when hand hygiene is inadequate.
Symptoms of STEC infection typically begin three to four days after exposure, though the range spans one to nine days. The hallmark presentation includes severe abdominal cramps and diarrhea that often becomes bloody. Fever is typically low-grade or absent. Most healthy individuals recover within five to seven days without specific treatment. However, the severity or presence of certain symptoms depends on the specific pathogenic strain involved.
Hemolytic Uremic Syndrome: The Most Serious Complication
The most serious complication of STEC infection is hemolytic uremic syndrome (HUS), a condition characterized by the destruction of red blood cells, acute kidney injury, and low platelet count. HUS occurs when Shiga toxins enter the bloodstream and damage the endothelial cells lining small blood vessels, particularly in the kidneys. This damage triggers a cascade of events including microangiopathic hemolytic anemia, thrombocytopenia, and renal failure.
Approximately 5 to 10% of individuals diagnosed with STEC O157 infection develop HUS. In Western countries, bloody diarrhea in children is related to STEC infection in at least 6% of cases, rising to 15 to 20% during summer months. Approximately 15% of these pediatric STEC infections progress to HUS. Children under five years of age are at greatest risk, followed by older adults and immunocompromised individuals.
HUS is the principal cause of acute kidney failure in children. Approximately half of patients with HUS require dialysis during the acute phase. While most recover normal renal function, approximately 30% will suffer long-term renal sequelae, with the risk increasing if the duration of anuria exceeds five days. Long-term follow-up studies have shown that five years after HUS recovery, 20% of children exhibit microalbuminuria, a marker of kidney damage, compared with 3% of controls, and demonstrate a measurable decrease in glomerular filtration rate. Long-term HUS sequelae include abnormal renal function in approximately 10 to 30% of patients, with some requiring ongoing dialysis.
Complications of HUS extend beyond the kidneys. Patients may experience high blood pressure, seizures, blood-clotting problems, stroke, or coma. In severe cases, STEC infections can lead to bowel necrosis, perforation, rectal prolapse, peritonitis, and intussusception.
A critical clinical consideration is that antibiotics are generally not recommended for STEC infections. Treatment with antibiotics can promote the development of HUS by increasing the release of Shiga toxins from dying bacteria. Management focuses on supportive care, including rehydration and close monitoring for signs of HUS. Early volume expansion with isotonic crystalloid solutions has been shown to mitigate the severity of HUS in pediatric patients.
Historical Context: Major STEC Outbreaks
The 2026 sprouts outbreak is the latest in a series of significant STEC outbreaks that have shaped food safety policy and public health practice in the United States and globally.
The 1993 Jack in the Box Outbreak
The most consequential STEC outbreak in U.S. history occurred in 1993, when undercooked hamburger patties contaminated with E. coli O157:H7 were served at Jack in the Box restaurants across several western states. The outbreak sickened more than 700 people and resulted in 171 hospitalizations and four deaths, all of them children. The CDC had identified E. coli O157 as a cause of human illness in 1982, linking it to bloody diarrhea and kidney damage. By the time of the Jack in the Box outbreak, researchers understood that E. coli O157 produces a toxin capable of damaging not just the intestines but also the kidneys, leading to HUS and death.
The Jack in the Box outbreak fundamentally altered the regulatory landscape for meat safety. It led to the classification of E. coli O157:H7 as an adulterant in ground beef, established a zero-tolerance policy, and drove the creation of two CDC systems that remain central to outbreak detection today: FoodNet, which tracks foodborne illnesses and measures prevention effects, and PulseNet, which uses bacterial subtyping to detect multistate outbreaks.
The 2011 German Sprout Outbreak
The largest STEC outbreak ever recorded occurred in Germany in 2011, caused by an unusual serotype, O104:H4, that combined Shiga toxin production with enhanced adherence properties. The outbreak ultimately involved more than 4,000 persons across 16 countries. In Germany alone, 3,816 cases were reported, including 845 cases of HUS (22% of all cases) and 54 deaths. The food vehicle was ultimately identified as raw fenugreek sprouts. The outbreak highlighted the potential for non-O157 STEC serotypes to cause large-scale, severe illness and underscored the importance of laboratory testing for rare or novel STEC pathogens.
Sprout-Associated STEC Outbreaks
Sprouts have been repeatedly implicated in STEC outbreaks due to the warm, humid conditions required for seed germination, which also favor bacterial growth. Pathogens can become internalized within sprout tissue, making them difficult to remove through washing. In 1996, an outbreak of E. coli O157:H7 linked to radish sprouts in Sakai, Japan, affected approximately 10,000 people, with approximately 6,000 culture-confirmed cases and 12 deaths. A separate sprout-related outbreak in Japan in 1993, caused by a different E. coli serotype, affected more than 2,000 people.
The CDC has documented that since 1996, there have been at least 30 reported outbreaks of foodborne illness associated with raw and lightly cooked sprouts in the United States, most caused by Salmonella and E. coli.
The 2018 to 2019 Romaine Lettuce Outbreaks
Leafy greens have also been a recurring vehicle for STEC. A reoccurring strain of STEC O157 caused two multistate outbreaks linked to romaine lettuce in 2018 and 2019, resulting in 234 illnesses across 33 states. The fall 2018 outbreak alone resulted in 62 reported illnesses in 16 states and the District of Columbia. The recurrence of the same strain across multiple growing seasons highlighted systemic challenges in preventing contamination of leafy greens, including the role of agricultural water, wildlife intrusion, and proximity of livestock operations to produce fields.
The 2024 McDonald’s Onion Outbreak
More recently, in 2024, sliced onions supplied by Taylor Farms and served on McDonald’s Quarter Pounders were contaminated with E. coli, resulting in one death and at least 100 illnesses. This outbreak demonstrated that even large, sophisticated food suppliers with substantial food safety investments remain vulnerable to contamination events.
Broader Impact and Prevention
STEC infections remain a substantial public health burden in the United States. The CDC estimates that Shiga toxin-producing E. coli cause more than 265,000 illnesses annually, resulting in more than 3,600 hospitalizations and 30 deaths. Approximately 5 to 10% of STEC O157 cases develop HUS. Of the roughly 97,000 O157 infections estimated to occur each year in the United States, approximately 3,270 lead to hospitalization.
Prevention of STEC infection relies on established food safety practices. Key measures include thorough handwashing after using the bathroom, changing diapers, or handling raw meat; cooking ground beef to an internal temperature of at least 160°F; avoiding raw or unpasteurized milk, juices, and cider; preventing cross-contamination between raw meat and ready-to-eat foods; and washing raw fruits and vegetables before consumption.
For sprouts specifically, the FDA and CDC have advised that individuals at higher risk for foodborne illness, including young children, older adults, pregnant women, and immunocompromised persons, should avoid consuming raw or lightly cooked sprouts entirely. Because pathogens can be internalized within sprout tissue, washing cannot reliably remove contamination. Cooking sprouts thoroughly is the only reliable method to eliminate pathogens.
The 2026 sprouts outbreak serves as a reminder that despite advances in food safety regulation and technology, STEC remains a persistent threat. The outbreak’s multi-pathogen nature, involving several distinct STEC serotypes alongside Salmonella, further illustrates the complexity of investigating and containing contamination events in the modern food supply chain. The FDA’s investigation remains ongoing, with the agency continuing to work with state and federal partners to determine whether additional products or firms are linked to illnesses.
