Sprout outbreak traced to contaminated seed supplier grows to 76 cases in 16 states

Federal health officials said this week that a multistate outbreak of foodborne illness linked to alfalfa sprouts has grown to 76 confirmed cases across 16 states, as investigators traced the contamination to a single seed supplier whose product reached at least two commercial sprout growers. The Centers for Disease Control and Prevention and the Food and Drug Administration updated their case counts on Oct. 1, adding 21 patients and one additional state since officials first disclosed the outbreak in late August.

The outbreak is notable among food-safety investigators for involving two distinct pathogens from a single contaminated source: Shiga toxin-producing E. coli and Salmonella Agona. Health officials say that combination is unusual and points to a shared point of contamination further up the supply chain, rather than contamination that occurred separately at each grower's facility.

The numbers

According to the CDC's most recent investigation update, 64 of the 76 confirmed patients were infected with E. coli, nine with Salmonella, and three with both pathogens. Six people have been hospitalized, a hospitalization rate of roughly 9 percent among the patients for whom outcome data is available. No deaths have been reported.

Illness onset dates range from May 31 to Sept. 7, indicating the outbreak has been active for more than three months before being fully traced to its source. Cases have been confirmed in Florida, Indiana, Iowa, Kansas, Michigan, Minnesota, New Hampshire, New York, North Carolina, North Dakota, Oregon, Pennsylvania, South Carolina, South Dakota, Washington and Wisconsin, with the heaviest concentrations in Minnesota and Wisconsin, where the outbreak was first detected.

Three strains of E. coli have been identified in patient samples: O26:H11, O103:H25 and O168:H8. Investigators say the presence of multiple E. coli serotypes alongside a Salmonella strain in the same product is itself a marker of a diffuse, systemic contamination event rather than an isolated batch problem.

How the outbreak was traced

Epidemiologic interviews played a central role in confirming the link to sprouts. Of 50 patients interviewed by investigators, 40 reported eating sprouts in the week before becoming ill, and 35 specifically recalled eating alfalfa sprouts — a proportion far higher than the roughly 9 percent of the general population that reports eating sprouts in a given week, according to CDC reference data cited in the investigation.

Traceback work by the FDA initially implicated Everything Sprouts LLC, a Minneapolis grower that distributed alfalfa sprouts and sprout mixes under the Everything Sprouts and Calco brand names to restaurants and grocery stores in Minnesota and Wisconsin. The company recalled affected lots starting Aug. 22, including its Crunchy Protein Sprout Mix, Zesty Garlic Mix and Robust Radish Sprout Mix.

But the investigation did not stop there. FDA inspectors, working with state partners, identified a second sprout grower that had received seed from the same source and used it to produce finished sprouts that also tested positive for the outbreak strains. That finding redirected the inquiry upstream, to the seed itself rather than to any single grower's sanitation practices.

The trail led to Berlin Seeds, a Millersburg, Ohio, company that sells alfalfa sprouting seed through a retail store and online. On Sept. 23, Berlin Seeds recalled 950 pounds of alfalfa sprouting seed from lot SAL2-24JB, sold in quarter-pound through 50-pound packages between Feb. 13 and Aug. 23 to customers in more than 40 states. The company said in its recall notice that a supplier had notified it that the seed had been traced to a grower whose finished sprouts were under FDA investigation, and that a sample of spent irrigation water from the seed lot had separately tested positive for E. coli.

"The recall was initiated after our seed supplier notified us that the seeds were identified through traceback as seed used by a sprout grower whose finished sprouts were part of an FDA investigation," Berlin Seeds said in its recall announcement.

Who is affected

The product distribution footprint is considerably wider than the current case count suggests. While confirmed illnesses have been reported in 16 states, the FDA says Berlin Seeds' recalled seed lot was shipped to customers in 42 states and Puerto Rico, and finished sprout products grown from related seed reached an even broader distribution network of wholesalers, grocery stores and restaurants. Federal officials have cautioned that additional illnesses may still be identified as the investigation continues, since the incubation period for both pathogens means recently exposed people may not yet have developed symptoms or been tested.

Home sprouters who purchased Berlin Seeds alfalfa sprouting seed with lot code SAL2-24JB, and consumers who may still have Everything Sprouts or Calco brand alfalfa sprouts, Crunchy Protein Sprout Mix, Zesty Garlic Mix or Robust Radish Sprout Mix in their refrigerators, are advised to discard the products rather than eat them, even if some appears unaffected. Raw sprouts are a recurring source of outbreaks because the warm, humid conditions needed to germinate seeds are also ideal for bacterial growth, and the sprouts themselves cannot be effectively washed free of contamination once seeds are infected.

What officials are advising

The CDC is urging anyone who bought the recalled products not to eat, sell or serve them, and to wash and sanitize any surfaces, containers or utensils that may have come into contact with them. People who develop symptoms after eating raw sprouts — including diarrhea, stomach cramps, fever or vomiting — are advised to contact a health care provider, particularly if diarrhea is bloody, which officials describe as a warning sign of more serious E. coli infection requiring prompt medical attention.

Shiga toxin-producing E. coli infections typically cause symptoms within three to four days of exposure, with illness lasting about a week in most cases, though a small share of patients — particularly young children and older adults — can develop a severe kidney complication called hemolytic uremic syndrome. Salmonella infections generally produce symptoms within 12 to 72 hours and resolve within four to seven days without treatment in most healthy adults.

What happens next

The FDA says its investigation remains open, with traceback work continuing to determine whether other seed lots, growers or distributors may have received contaminated product from the same supply chain. Agency officials have not ruled out additional recalls as the inquiry proceeds. The agency has also signaled continued scrutiny of Everything Sprouts' Minneapolis facility, where earlier inspections identified sanitation concerns, including a leaking roof dripping water onto sprouts and onto workers' protective clothing.

Food-safety specialists note that sprout-related outbreaks are difficult to prevent entirely because seeds can carry low levels of contamination that are undetectable before germination, and current seed-testing protocols are voluntary rather than mandatory under federal rules. Consumer advocates have periodically called on the FDA to require more rigorous pathogen testing of sprouting seed lots before they reach growers, a debate likely to resurface as this investigation concludes. In the meantime, federal health agencies continue to advise that children, older adults, pregnant women and people with weakened immune systems avoid raw sprouts of any kind, given their consistent association with outbreaks over the past three decades.