FDA Investigated Multistate Outbreak of Salmonella Infections Linked to Alfalfa Sprouts

May 13, 2016

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The U.S. Food and Drug Administration along with the Centers for Disease Control and Prevention (CDC) and state and local officials investigated a multi-state outbreak of Salmonella infections.

Update: May 13, 2016

On May 13, 2016, CDC reports that this outbreak appears to be over.

What was the Problem and What was Done About It?

The FDA, CDC, state and local officials investigated a multi-state outbreak of Salmonella illnesses linked to alfalfa sprouts.

The CDC reports that 26 people were infected with the outbreak strains of Salmonella Muenchen (25 people), or Salmonella Kentucky (1 person), as reported from 12 states. Eight people were hospitalized and no deaths were reported.

In February 2016, state and local health and regulatory officials in several states traced back the source of the sprouts from multiple restaurant locations where ill people ate them, and identified Sweetwater Farms of Inman, Kansas, as a supplier of alfalfa sprouts to all of these locations. The FDA collected and tested irrigation water and alfalfa sprout samples from Sweetwater Farms LLC and found Salmonella Kentucky and Salmonella Cubana. Salmonella Muenchen was not isolated.

On February 19, 2016, FDA and other federal, state, and local agencies briefed Sweetwater Farms LLC on their findings, and the firm voluntarily recalled alfalfa sprouts grown from a specific seed lot.

On February 26, 2016, Sweetwater Farms informed the FDA that it would recall all of its sprout products from the market.

After the recalls by Sweetwater Farms were completed, Salmonella Muenchen illnesses were still reported by people who reported eating alfalfa sprouts before they got sick. FDA traceback investigations indicated that several sprouters other than Sweetwater Farms produced the alfalfa sprouts these ill people ate. All of these sprouters, as well as Sweetwater Farms, used the same seed lot.

FDA tested samples of seeds from this lot and isolated Salmonella Cubana with the same DNA fingerprint of the Salmonella Cubana isolated in irrigation water from Sweetwater Farms. FDA contacted the seed supplier, who then called for the return of the contaminated seed lot from growers. The seed supplier is not named here because FDA is prohibited by law from releasing certain information about supply chains, which may constitute confidential commercial information. However, FDA has been able to confirm that all domestic sprouters who received contaminated seeds either returned or destroyed the seeds, and the shelf life of all sprouts grown from this seed lot has expired. Therefore, no sprouts from the contaminated seed lot are expected to be on the market.

On May 13, 2016, CDC reports that this outbreak appears to be over. FDA has provided the sprouters with information on reducing microbial food safety hazards for sprouted seeds and complying with new standards for growing, harvesting, packing, and holding of produce for human consumption under the Produce Safety Rule, which begins to go into effect for sprouters in January 2017 with additional time for small and very small operations. In particular, covered sprouters will now be required to comply with sprout-specific requirements such as treating seeds to reduce the presence of microorganisms of public health significance, testing the growing environment for Listeria as well as testing each production batch of spent sprout irrigation water or sprouts for E. coli O157:H7, Salmonella species and, under certain conditions, other pathogens. In addition, sprouters would be expected to comply with all other applicable requirements of the Produce Safety Rule, such as requirements related to worker health and hygiene, agricultural water and buildings, tools and equipment.

What are the Symptoms of Salmonella?

Most people infected with Salmonella develop diarrhea, fever, and abdominal cramps. The illness usually lasts 4 to 7 days, and most people recover without treatment.

How Soon do Symptoms Appear After Exposure?

Most people infected with Salmonella develop diarrhea, fever, and abdominal cramps 12 to 72 hours after infection.

What are the Complications of Salmonella Infections?

In some people, the diarrhea may be so severe that they need to be hospitalized. In these patients, the Salmonella infection may spread from the intestines to the blood stream, and then to other body sites and can cause death unless the person is treated promptly with antibiotics.

Who is at Risk?

Children are the most likely to get salmonellosis. The rate of diagnosed infections in children less than five years old is higher than the rate in all other people. Children younger than five, the elderly, and those people with weakened immune systems are more likely to have severe infections. It is estimated that approximately 400 persons in the United States die each year with acute salmonellosis. Children, the elderly, pregnant women, and people with weakened immune systems should avoid eating raw sprouts of any kind.

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What Do Restaurants and Retailers Need To Do?

Retailers, restaurants, and other food service operators who have served any potentially contaminated products need to be concerned about cross contamination of cutting surfaces and utensils through contact with the potentially contaminated products. They should follow the steps below:

  • Wash and sanitize display cases and refrigerators where potentially contaminated products were stored.
  • Wash and sanitize cutting boards, surfaces, and utensils used to prepare, serve, or store potentially contaminated products.
  • Wash hands with hot water and soap following the cleaning and sanitation process.
  • Regular frequent cleaning and sanitizing of food contact surfaces and utensils used in food preparation may help to minimize the likelihood of cross-contamination.

What Do Consumers Need To Do?

People who think they might have become ill from eating possibly contaminated alfalfa sprouts should talk to their health care providers. 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 used for sprouting are also ideal for the growth of bacteria, including Salmonella, Listeria, and E. coli. Any bacteria present can multiply dramatically during the sprouting process. (Organic or locally-grown sprouts are not necessarily less risky, and neither are sprouts grown at home.) Washing sprouts may reduce risk, but will not eliminate it.

Consumers should always practice safe food handling and preparation measures. Wash hands, utensils, and surfaces with hot, soapy water before and after handling food.

For refrigerators and other food preparation surfaces and food cutting utensils that may have come in contact with the potentially contaminated sprouts, it is very important that the consumers thoroughly clean these areas and items.

Consumers should follow these simple steps:

  • Wash the inside walls and shelves of the refrigerator, cutting boards and countertops; then sanitize them with a solution of one tablespoon of chlorine bleach to one gallon of hot water; dry with a clean cloth or paper towel that has not been previously used. 
  • Wash hands with warm water and soap for at least 20 seconds before and after handling food.
  • Wipe up spills in the refrigerator immediately and clean the refrigerator regularly.
  • Always wash hands with warm water and soap following the cleaning and sanitization process. 
  • Children, the elderly, pregnant women, and persons with weakened immune systems should avoid eating raw sprouts of any kind.
  • Cooking sprouts thoroughly will kill any bacteria present and reduce the risk of illness.
  • Persons who think they might have become ill from eating potentially contaminated sprouts should consult their health care provider.

Who Should be Contacted?

People who think they might have become ill from eating possibly contaminated alfalfa sprouts should talk to their health care providers. Contact your healthcare provider if you have diarrhea that lasts for more than 3 days, or is accompanied by high fever, blood in the stool, or so much vomiting that you cannot keep liquids down and you pass very little urine.

The FDA encourages consumers with questions about food safety to call 1-888-SAFEFOOD or consult the website:

The information in this release reflects the FDA’s best efforts to communicate what it has learned from the manufacturer and the state and local public health agencies involved in the investigation. The agency will update this page as more information becomes available.

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Page Last Updated: 05/13/2016
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