Red Book Online Outbreaks: Listeria Outbreak Linked to Supplemental Shakes

Updated: 02/26/2025

Overview

CDC is currently investigating a multistate Listeria monocytogenes outbreak linked to recalled supplemental shakes manufactured by Prairie Farms.  As of February 21, 2025, 38 people infected with the outbreak strain of Listeria monocytogenes have been reported from 21 states. Sick people's samples were collected on dates ranging from August 17, 2018, to January 23, 2025. Of 38 people with information available, 37 have been hospitalized. Twelve deaths have been reported from California, Illinois, Indiana, Michigan, Minnesota, North Carolina, New York, Tennessee, Texas, and Washington. Most people in this outbreak reported living in long-term care facilities or were hospitalized prior to becoming sick.

Recalled Food: 4 oz. Lyons ReadyCare and Sysco Imperial Frozen Supplemental Shakes. See recall notice for detailed product list.

Clinical Guidance

Presentation

• Listeria usually causes common food poisoning signs and symptoms, like fever and diarrhea. People who experience these symptoms usually recover without treatment. Symptoms of self-limited febrile gastroenteritis usually start within 24 hours of ingesting contaminated food and last 2-3 days.
• Less commonly, Listeria can cause severe illness (known as invasive listeriosis) when the bacteria spread beyond the gut to other parts of the body. Symptoms of invasive listeriosis usually start 1 to 4 weeks after eating contaminated food but may occasionally start even later.

• Pregnant people with invasive listeriosis usually experience only fever, fatigue, muscle aches, and occasionally gastrointestinal tract infections.
• Non-pregnant people with invasive listeriosis may experience headaches, stiff neck, confusion, loss of balance, and convulsions, in addition to fever and muscle aches.

• Patients should be seen by their pediatrician right away if they exhibit any signs or symptoms of Listeria

Who is at the highest risk/complications?

• People who are 65 years or older, are pregnant, or are immunocompromised.
• Listeria can cause pregnancy loss or premature birth.
• Listeria can also cause serious illness or death in newborns.

Diagnosis

• L monocytogenescan be recovered readily on blood agar from cultures of blood, cerebrospinal fluid (CSF), meconium, placental or fetal tissue specimens, amniotic fluid, and other infected tissue specimens, including joint, pleural, or peritoneal fluid. 
• Polymerase chain reaction (PCR) assays can be used to detect L monocytogenesin blood and CSF. 
• Stool cultures are generally not useful for the diagnosis of Listeria

Precautions

• People should not eat or drink recalled products.  Advise them to throw away or return them to the place of purchase.
• Advise people to clean their refrigerator, containers, and surfaces that may have touched the recalled foods. Listeria can survive in the refrigerator and can easily spread to other foods and surfaces.

Risk Mitigation

• Antimicrobial therapy for infection diagnosed during pregnancy may prevent fetal or perinatal infection and its consequences.

Treatment

• Combination therapy using ampicillin and a second agent in doses appropriate for meningitis is recommended for severe infections. An aminoglycoside, typically gentamicin, usually is used as the second agent in combination therapy. Use of an alternative second agent that is active intracellularly (eg, trimethoprim-sulfamethoxazole [contraindicated in infants younger than 2 months], fluoroquinolones, linezolid, or rifampin) is supported by case reports in adults. If alternatives to gentamicin are used, susceptibility should be confirmed because resistance to trimethoprim-sulfamethoxazole, fluoroquinolones, linezolid, or rifampin occasionally has been reported. In the penicillin-allergic patient, options include either penicillin desensitization or use of either trimethoprim-sulfamethoxazole or a fluoroquinolone, both of which have been used successfully as monotherapy for Listeria meningitis and in the setting of brain abscess. Treatment failures with vancomycin have been reported. Cephalosporins are not active against monocytogenes.

For bacteremia without associated central nervous system infection, 14 days of treatment is recommended. For L monocytogenes meningitis, most experts recommend 3 to 4 weeks of treatment. Longer courses are necessary for patients with endocarditis or parenchymal brain infection (cerebritis, rhombencephalitis, brain abscess). Iron may enhance the pathogenicity of L monocytogenes; iron supplements should be withheld until treatment for listeriosis is complete. Diagnostic imaging of the brain near the end of the anticipated duration of therapy allows determination of parenchymal involvement of the brain and the need for prolonged therapy in neonates with complicated courses and in immunocompromised patients.

Reporting

• Listeriosis is a nationally notifiable disease in the United States.
• Cases should be reported promptly to the state or local health department to facilitate early recognition and control of common-source outbreaks.
• Clinical isolates should be forwarded to a public health laboratory for genetic sequencing.

Resources

• For more information see the Red Book chapters on:
  • Listeria monocytogenes Infections (Listeriosis)
  • Prevention of Infectious Disease From Contaminated Food Products