CDC News: Sprout Outbreaks Over After 111 Sick in 19 States

CDC news on Monday brought the end of a food safety scare that had stretched across the summer and into the fall. The Centers for Disease Control and Prevention has declared an end to a dual outbreak of E. coli and Salmonella traced to alfalfa sprouts and the seeds used to grow them, closing an investigation that began in August. The announcement, made on November 9, came five days after the agency closed a second, separate outbreak linked to broccoli sprouts. Between the two outbreaks, 111 people fell sick in 19 states, and nine were hospitalized. There were no deaths. The outbreaks are over, but the story behind them is a warning about a food safety problem that regulators have been trying to solve for years.

The alfalfa sprout outbreak was the larger and more unusual of the two. It was traced to Everything Sprouts of Minneapolis, Minnesota, and Berlin Seeds of Millersburg, Ohio, and it was unusual because it involved more than one pathogen. Patients were infected with Salmonella Agona and with three strains of E. coli, identified as O26:H11, O103:H25 and O168:H8. The outbreak caused at least 77 illnesses in 16 states, with six hospitalizations and no deaths. Sixty-four outbreak patients were infected with E. coli, 10 people were infected with Salmonella, and three people were infected with both Salmonella and E. coli. Illnesses started on dates ranging from May 31 to October 19, a span of nearly five months.

CDC News: The Seed Lot Behind the Outbreak

The investigation pointed to a single source: a lot of alfalfa seed identified as SAL2-24JB, with an expiration date of December 31, 2029. The Food and Drug Administration, which investigated alongside the CDC and state and local partners, said the recalled seed lot should not be sold, used or distributed. The agency closed its investigation on November 9, the same day the CDC declared the outbreak over. In its final update, the FDA said the recalled lot should no longer be available for sale, but it also noted that the lot carries an expiration date more than three years in the future, which means any remaining seed could still be in storage somewhere.

That detail is what makes the story more than a routine outbreak closure. The FDA knows the name of the seed supplier, but it has refused to publicly reveal it. Instead, the agency has reported only the lot number, leaving growers and sellers to check their own inventories against a code. The FDA's announcement said plainly that sprout growers should check their inventory for the recalled seed lot and discard any remaining seed. It is a system that depends on the industry policing itself, and it has drawn criticism from food safety advocates who argue that the public deserves to know who supplied the contaminated seed.

The broccoli sprout outbreak, closed on November 4, followed a similar pattern. It was linked to Salmonella Bovismorbificans, and the seed behind it was imported from New Zealand and sold by a domestic supplier, which recalled the lot identified as W4105. The two outbreaks were not related. They involved different growers, different seeds, different bacteria and different parts of the country. And yet they are the same story in the way that matters most. In both cases, the contaminated seed lot was the source, and in both cases, the sprouts grown from that seed carried the bacteria to the people who ate them.

Why Sprouts Keep Causing Outbreaks

Sprouts have been a recurring source of foodborne illness for decades, and the reason is built into how they are grown. Seeds are sprouted in warm, moist conditions that are ideal for growing plants, and those same conditions are ideal for growing bacteria. If a seed lot is contaminated, the bacteria multiply as the sprouts grow, and washing the finished sprouts does not reliably remove them. The risk is well known to regulators and to the industry, and it is the reason sprouts carry warnings that other fresh produce does not.

The numbers show how small the exposed population is, and how serious the consequences can be. In the CDC's FoodNet survey, only 8.7 percent of healthy people report eating any sprouts in a week. Sprouts are a niche food, eaten by a small fraction of the population. But when a contaminated lot reaches the market, the people who do eat sprouts are exposed to a concentrated risk, and the illnesses that follow can be severe. E. coli and Salmonella infections can cause diarrhea, stomach cramps, fever and vomiting, and in some cases they lead to hospitalization. For people with weakened immune systems, young children and older adults, the risk is higher.

The seed problem is the hardest part to solve. Seeds are traded globally, and a single lot can be sold to many growers in many states. The broccoli seed in this year's outbreak was imported from New Zealand. The alfalfa seed lot at the center of the larger outbreak has not been publicly traced to a named supplier, which means the full path from the seed producer to the sprout grower to the consumer remains partly hidden. Food safety experts have argued for years that the seed supply chain needs more transparency and more testing, and these two outbreaks are the latest evidence for that argument.

How the Investigation Unfolded

The investigation began in August, when the CDC and the FDA started looking into reports of E. coli and Salmonella infections that shared a common thread: the patients had eaten alfalfa sprouts. As the case count grew, the agencies worked with state and local health departments to interview patients, trace the sprouts back to their growers, and test the seed lots the growers had used. The work led to Everything Sprouts, which recalled its alfalfa sprouts on August 22, and to the seed lot SAL2-24JB, which the FDA identified as the source.

The broccoli sprout investigation ran on a parallel track. The CDC declared that outbreak over on November 4, after the FDA completed its investigation into Salmonella contamination linked to the imported seed lot W4105. The two investigations were separate, but they were conducted by the same agencies, using the same methods, and they reached the same conclusion: the seed was the source, and the outbreaks ended when the seed was removed from the supply chain.

The CDC posted final data for each outbreak, including where people got sick and when their illnesses began. For the alfalfa outbreak, the onset dates ran from May 31 to October 19, which means the contaminated sprouts were reaching consumers for nearly five months before the outbreak was declared over. The long tail is typical of sprout outbreaks, because the seed can sit in storage for months before it is used, and the sprouts grown from it can be sold over a period of weeks. It is also a reminder that declaring an outbreak over does not mean the risk has vanished: any remaining seed from the recalled lot could still cause illness if it is planted.

What Consumers and Growers Should Do Now

For consumers, the immediate advice is straightforward. Anyone who bought alfalfa sprouts or broccoli sprouts in recent months and still has them at home should check whether they are part of a recall, and discard them if there is any doubt. More generally, health officials advise people who are at higher risk of foodborne illness, including young children, older adults, pregnant women and people with weakened immune systems, to avoid eating raw sprouts altogether. Cooking sprouts kills the bacteria that cause illness, and it is the only reliable way to make them safe.

For sprout growers, the FDA's message is equally direct. Growers should check their inventory for the recalled seed lot SAL2-24JB and discard any remaining seed. The agency has said the lot should no longer be available for sale, but the expiration date of December 31, 2029, means that seed from the lot could still be sitting in a warehouse or a storeroom. The responsibility for finding it and removing it falls on the growers and the suppliers who hold it, and the FDA's decision not to name the supplier makes that job harder, not easier.

The broader lesson is about the seed supply chain itself. Two outbreaks, two different seeds, two different bacteria, and the same root cause. Until the seed that sprout growers buy is tested more rigorously and traced more transparently, outbreaks like these will keep happening. The agencies that investigate them have the tools to find the source, as they did here. What they do not yet have is a system that prevents the contaminated seed from reaching the grower in the first place.

What Happens Next

Both investigations are now closed, and the CDC has declared both outbreaks over. The FDA's outbreak investigation is complete. But the work that follows an outbreak, the recalls, the inventory checks, the review of what went wrong, continues. The seed lot SAL2-24JB remains the central concern: as long as any of it exists, there is a risk that it will be used. The FDA has said it should not be sold, used or distributed, and growers who find it in their inventory are expected to discard it.

For the 111 people who fell sick, the outbreaks are a personal story as well as a public health one. Nine of them were hospitalized. All of them recovered, or are recovering, from illnesses that could have been prevented. Their cases are now part of the data that regulators use to argue for stronger seed safety rules, and part of the record of a food safety problem that has persisted for decades. The outbreaks are over. The seed problem is not.

Source: Food Safety News