Federal officials are reporting that a deadly multi-year outbreak of Listeria monocytogenes infections traced to romaine lettuce is over.

As of March 8 the patient count stood at 10 with one person in Pennsylvania having died, according to statements from the Food and Drug Administration and the Centers for Disease Control and Prevention. 

“The true number of sick people in this outbreak is likely higher than the number reported, and the outbreak may not have been limited to the states with known illnesses,” according to the CDC’s notice. “This is because some people recover without medical care and are not tested for Listeria.”

Also, it can take up to 70 days for symptoms of Listeria infection to develop and in those cases patients can rarely recall whether they consumed implicated foods.

The outbreak, first reported by the CDC on Dec. 22, 2021, was linked to romaine hearts sold under the Fresh Express brand. Illnesses had begun on July 26, 2016, and ran through Oct. 19, 2021, according to the CDC’s December announcement. The agency did not post any outbreak updates between December 2021 and March 8, 2022.

Even though all of the outbreak patients did not report specifically consuming Fresh Express salad, whole genome sequencing of samples from them showed that their infections came from the same subtype of the bacteria, suggesting a common food source, according to the CDC.

Sick people ranged in age from 44 to 95 years, with a median age of 80, and 60 percent were female.

Patients were identified in Illinois, Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania and Virginia. The implicated salad was distributed in 20 states, mostly in the upper MidWest and New England, suggesting that additional outbreak patients were likely part of this multi-year outbreak.

“On December 16, 2021, the Michigan Department of Agriculture and Rural Development identified the outbreak strain of Listeria in a bag of Fresh Express Sweet Hearts Romaine Lettuce Sweet Butter Lettuce packaged salad collected from a grocery store during routine sampling,” according to the CDC. “The packaged salad was produced at the Fresh Express facility in Streamwood, Illinois.”

Fresh Express initiated a recall on Dec. 20, according to the CDC and the FDA, for its Sweet Hearts Romaine Lettuce Sweet Butter Lettuce.

In its outbreak update on March 8 the FDA reported: “The product is past expiration and should no longer be available to consumers. Therefore, there are no recommendations for consumers, retailers, or suppliers.” 

However, because Listeria can survive refrigerated and freezing temperatures for long periods of time, the FDA continues to recommend that consumers who had the recalled product in their homes clean and sanitize any storage areas or containers used for the product.

About Listeria infections
Food contaminated with Listeria monocytogenes may not look or smell spoiled but can still cause serious and sometimes life-threatening infections. Anyone who develops symptoms of Listeria infection should seek medical treatment and tell their doctors about the possible Listeria exposure.

Also, anyone who has eaten any products reported to have been contaminated with Listeria monocytogenes should monitor themselves for symptoms for several weeks because it can take up to 70 days after exposure to symptoms of listeriosis to develop.

Symptoms of Listeria infection can include vomiting, nausea, persistent fever, muscle aches, severe headache, and neck stiffness. Specific laboratory tests are required to diagnose Listeria infections, which can mimic other illnesses.

Pregnant women, the elderly, young children, and people such as cancer patients who have weakened immune systems are particularly at risk of serious illnesses, life-threatening infections, and other complications. Although infected pregnant women may experience only mild, flu-like symptoms, their infections can lead to premature delivery, infection of the newborn, or even stillbirth.

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