Listeria Outbreak Linked to Contaminated Milkshakes - Food Safety Concerns

The Listeria Outbreak Linked to Milkshakes

A concerning outbreak of listeriosis, caused by the bacteria Listeria monocytogenes, has been linked to contaminated milkshakes sold by a national chain. According to the CDC, over 100 people have been sickened so far across multiple states. At least 10 deaths have been reported. Investigators have traced the source back to a milkshake manufacturing facility that supplies pre-made milkshakes to thousands of stores and restaurants nationwide.

What is Listeria?

Listeria monocytogenes is a species of disease-causing bacteria that can contaminate food. When ingested, Listeria can cause an illness called listeriosis. Common symptoms include fever, muscle aches, nausea, and diarrhea. While healthy individuals may only experience mild, flu-like symptoms, listeriosis can be fatal in high-risk groups like the elderly, pregnant women, newborns, and those with weakened immune systems. Invasive listeriosis occurs when the bacteria spreads beyond the gut to infect other parts of the body. This can lead to serious complications like meningitis, encephalitis, miscarriage, or stillbirth.

The Investigation

The CDC, along with state and local health agencies, launched an investigation as soon as the first cases of listeriosis were reported. Using advanced DNA fingerprinting techniques, they were able to identify the outbreak strain in samples collected from sick individuals. Tracing back the supply chain, a strong epidemiological link was found between the contaminated milkshakes and the manufacturing facility that produced them before distribution. An inspection of the facility discovered likely points of Listeria contamination as well as lapses in sanitation protocols. The milkshake products were quickly recalled, and the facility was shut down for deep cleaning and revisions to food safety procedures.

How Does Listeria Contaminate Food?

Listeria monocytogenes is widespread in the environment and can be found in soil, water, and animal feces. The bacteria can live and grow under refrigeration temperatures and is resistant to acidity and salt. Common food sources of Listeria outbreaks include deli meats, unpasteurized dairy products, produce, and processed ready-to-eat foods. In commercial food processing, Listeria transmission commonly occurs through:

• Contaminated raw ingredients
• Unsanitary food contact surfaces
• Inadequate cooking or pasteurization
• Cross-contamination from food processing equipment

Stringent hygiene, cleaning protocols, employee training, and testing procedures are essential to limiting Listeria presence in manufacturing facilities.

Who is at High Risk?

Listeriosis primarily affects those with weakened immune systems who are not able to fight off infection effectively. High-risk groups include:

• Pregnant women and newborns
• Adults over 65 years of age
• People with HIV/AIDS
• Cancer patients receiving chemotherapy
• Individuals taking corticosteroids or immunosuppressive drugs
• Those with chronic diseases like diabetes, liver or kidney disease

Pregnant women need to be especially vigilant as even mild listeriosis can lead to pregnancy complications or neonatal infections. The CDC recommends avoiding high-risk foods like unpasteurized dairy, deli meats, and refrigerated pâtés or meat spreads unless thoroughly heated before serving.

Preventing Listeria Infection

For vulnerable populations, the risk of Listeria infection can be reduced by:

• Avoiding high-risk foods like soft cheeses, deli meats, hot dogs, and refrigerated smoked seafood
• Cooking raw meat, poultry, eggs, and seafood thoroughly
• Washing fruits and vegetables before use
• Keeping the refrigerator below 40°F and freezer below 0°F
• Avoiding cross-contamination in storage and preparation
• Reheating leftovers until steaming hot

Food businesses must adhere to strict controls including HACCP plans, employee training, vigorous sanitation, and regular testing for Listeria and other pathogens. With sound food safety practices, Listeria outbreaks can be prevented.

The Bottom Line

The milkshake-related listeriosis outbreak serves as an urgent reminder about the severe health risks this pathogen poses to those most vulnerable in our communities. Although the source has been identified and containment measures taken, listeriosis has a high hospitalization and fatality rate compared to other foodborne illnesses. It is imperative for manufacturers to guarantee the safety of ready-to-eat foods through robust controls against Listeria and other pathogens. With medical supervision, those at high risk can also take prudent steps to reduce their likelihood of infection.

FAQs

What are the symptoms of listeriosis?

Common symptoms include fever, muscle aches, nausea, vomiting, and diarrhea. Pregnant women may experience only mild, flu-like symptoms but the infection can lead to pregnancy complications or neonatal infections.

How do you treat listeriosis?

Listeriosis is treated with antibiotics, usually ampicillin injected into a vein. In serious cases, a combination of antibiotics may be needed. Newborns and pregnant women usually receive preventative antibiotics if the mother is diagnosed with listeriosis.

What foods are high-risk for listeriosis?

High-risk foods include deli meats, unpasteurized dairy products, soft cheeses, refrigerated smoked seafood, raw sprouts, and ready-to-eat foods like pre-cut fruits and vegetables.

How can you prevent listeriosis?

Cook raw meats thoroughly. Avoid high-risk foods unless they are reheated until steaming hot. Wash fruits and vegetables. Separate raw and cooked foods. Sanitize surfaces and utensils after contact with raw foods. Maintain refrigerator below 40°F.

Who is most at risk of infection?

Pregnant women, newborns, adults over 65, and those with weakened immune systems due to other medical conditions or medications are most at risk. People in these high risk groups should take extra precautions against listeriosis.