Red Book Online Outbreaks: Listeria Outbreak Linked to Ice Cream

Overview

CDC is currently investigating a Listeria monocytogenes outbreak linked to “Soft Serve on The Go” Ice Cream Cups and “Ice Cream House” Ice Cream and Frozen Dessert Products. As of September 1, 2023, 2 people (both hospitalized) in 2 states have been infected with Listeria monocytogenes possibly due to eating “Soft Serve On The Go” Ice Cream Cups and “Ice Cream House” Ice Cream and Frozen Dessert Products.

The outbreak strain of Listeria was found in an “Ice Cream House” mini dessert cigar (a novelty ice cream product) and “Soft Serve On The Go” ice cream cups. Both brands of ice cream products are made at The Ice Cream House.

On August 30, 2023, The Ice Cream House recalled all their dairy ice cream and non-dairy frozen dessert products with the "Ice Cream House" logo. Do not eat, sell, or serve recalled products.

Clinical Guidance

Presentation

• Listeriausually 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 infection after eating the ice cream.

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 “Soft Serve On The Go” ice cream cups.
  • People should check their freezers. Listeria can survive at freezing temperatures.
  • Throw them away or return them to where they were purchased for a refund.
  • If patients have any questions, they can contact the company at 845-668-4346 or info@softserveonthego.com (Monday to Friday, 9am to 5 pm EST).

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