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FDA Investigated Listeria monocytogenes in Sprouts from Wholesome Soy Products, Inc.

Posted January 29, 2015

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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 listeriosis. According to the CDC, the investigation was closed as of January 27, 2015.

What was the Problem and What was Done About It?

The FDA, CDC and state and local officials investigated five cases of listeriosis that occurred between June and August, 2014. The CDC reported that there were four cases in Illinois and one in Michigan. Five cases were hospitalized and two patients have died.

A routine FDA inspection from August 12 – September 3, 2014, at Wholesome Soy Products Inc. of Chicago Illinois, a manufacturer of sprouts, tofu, and soy products, identified the presence of Listeria monocytogenes. During the FDA inspection, the investigators collected mung bean sprouts and spent irrigation water sample collected during mung bean production. Two mung bean sprout samples and one spent irrigation water sample tested positive for Listeria monocytogenes. Additionally, FDA investigators collected additional environmental swabs, 25 of which showed the presence of Listeria monocytogenes.

On August 28, 2014, after being informed of the positive sample findings, Wholesome Soy Products Inc. agreed to perform a voluntary recall of its mung bean sprouts, and temporarily ceased production of that product.

On September 25, 2014, Whole Genome Sequencing analysis of the Listeria monocytogenes isolated from mung bean sprouts produced by Wholesome Soy Products Inc., spent sprout irrigation water, and the environmental swabs collected at the production facility, the strains were found to be highly related to sequences of Listeria monocytogenes strains isolated from five clinical samples representing the people who became ill from June through August 2014. The company reported cleaning and sanitizing its facility and the company’s independent consultant collected and tested several environmental samples. The company reported that these environmental samples tested negative for Listeria monocytogenes. Wholesome Soy Products Inc. resumed production of mung bean sprouts on September 15, 2014.

FDA investigators began a follow-up inspection of the Wholesome Soy Products Inc. facility on October 7, 2014 to verify the actions taken by the company. During this inspection, investigators collected samples of mung bean sprouts, soy bean sprouts, tofu; spent irrigation water, and seeds, as well as environmental samples.

On October 10, 2014, Wholesome Soy Products Inc. representatives had reported that the firm had ceased tofu and soy drink production, although mung bean sprout production and distribution has continued.

On October 16, 2014, nine of the environmental samples, or swabs, taken by FDA investigators as part of the October inspection identified the presence of Listeria monocytogenes. On November 3, 2014, based on WGS analysis, these nine samples were found to be highly related to the Listeria monocytogenes from the samples collected from the firm in August and September, as well as to the samples from the five case patients.

On November 7, 2014, Wholesome Soy Products Inc. of Chicago, Ill., verbally agreed to close their facility and to cease production and distribution of mung bean sprouts. Mung bean sprouts produced by Wholesome Soy Products Inc. are likely no longer available for purchase or consumption, given the five-day shelf life for sprouts reported by the facility.

As of November 10, 2014, the firm issued a letter to its customers and employees informing them that Wholesome Soy Products Inc. had permanently ceased operations. Mung bean and soy bean sprouts, tofu products, and other soy goods are no longer being manufactured by Wholesome Soy Products Inc.  According to the CDC, the investigation was closed as of January 27, 2015.

What are the Symptoms of Listeriosis? 

Listeriosis is a rare but serious illness caused by eating food contaminated with the bacteria called Listeria monocytogenes. Anyone who experiences fever and muscle aches, sometimes preceded by diarrhea or other gastrointestinal symptoms, or develops fever and chills after eating sprouts should seek medical care and tell their health care provider about any history of eating the sprouts. Symptoms can appear from a few days up to a few weeks after consumption of the contaminated food. 

Who is at Risk?

Listeriosis can be fatal, especially in certain high-risk groups. These groups include the elderly, and people with weakened immune systems and certain chronic medical conditions (such as cancer). In pregnant women, listeriosis can cause miscarriage, stillbirth, premature labor, and serious illness or death in newborn babies.

What Do Consumers Need To Do?  

Consumers should not eat any mung bean or soy bean sprouts or other products produced by Wholesome Soy Products Inc. of Chicago, Ill. If consumers have such products, they should dispose of them in the garbage.

These products are no longer available for purchase from Wholesome Soy Products Inc.

Recommendations for preventing listeriosis are available at the CDC Listeria website:  

Listeria monocytogenes can grow at refrigerator temperatures, as low as 40 degrees Fahrenheit (4 degrees Celsius). The longer ready-to-eat refrigerated foods are stored in the refrigerator, the more opportunity Listeria has to grow.   

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

  • 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. 

Consumers should follow these simple steps:

  • 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. 

What Do Retailers and Restaurants Need To Do?  

Restaurants and retailers should not sell or serve any products produced by Wholesome Soy Products Inc. of Chicago, Ill.  If you do not know the source of your sprouts, check with your supplier.

These products are no longer available for purchase from Wholesome Soy Products Inc.

  • Wash and sanitize display cases and refrigerators where potentially contaminated products were stored.
  • Wash and sanitize cutting boards, surfaces, and utensils used to cut, serve, or store potentially contaminated products.
  • Wash hands with warm water and soap following the cleaning and sanitation process. 
  • Retailers, restaurants, and other food service operators who have processed and packaged any potentially contaminated products need to be concerned about cross contamination of cutting surfaces and utensils through contact with the potentially contaminated products.
  • Regular frequent cleaning and sanitizing of cutting boards and utensils used in processing may help to minimize the likelihood of cross-contamination. 

Listeria can grow at refrigeration temperatures in foods like sprouts. Listeria can also cross contaminate other food cut and served on the same cutting board or stored in the same area. Retailers, restaurants, and other food service operators may wish to consider whether other foods available for sale could have been cross-contaminated from the potentially contaminated products, and should be discarded.  

Who Should be Contacted? 

The FDA encourages consumers with questions about food safety to call 1-888-SAFEFOOD Monday through Friday between 10 a.m. and 4 p.m. Eastern time, or to consult

The information in this posting reflects the FDA’s best efforts to communicate what it has learned from the manufacturer, the CDC, 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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