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Published on: May 6, 2013
Hospital-acquired listeriosis linked to a persistently contaminated milkshake machine
E Mazengia1, V Kawakami2, K Rietberg2
1Food Protection Program of Environmental Health Division,Public Health - Seattle & King County,Seattle,WA,USA.
Abstract:
One case of hospital-acquired listeriosis was linked to milkshakes produced in a commercial-grade shake freezer machine. This machine was found to be contaminated with a strain of Listeria monocytogenes epidemiologically and molecularly linked to a contaminated pasteurized, dairy-based ice cream product at the same hospital a year earlier, despite repeated cleaning and sanitizing. Healthcare facilities should be aware of the potential for prolonged Listeria contamination of food service equipment. In addition, healthcare providers should consider counselling persons who have an increased risk for Listeria infections regarding foods that have caused Listeria infections. The prevalence of persistent Listeria contamination of commercial-grade milkshake machines in healthcare facilities and the risk associated with serving dairy-based ice cream products to hospitalized patients at increased risk for invasive L. monocytogenes infections should be further evaluated.
Insights
Hospital-acquired listeriosis outbreaks can stem from contaminated milkshake machines, even after cleaning. Healthcare facilities must address persistent Listeria contamination risks in food equipment.
Area of Science:
- Food safety in healthcare settings
- Microbiology of foodborne pathogens
- Hospital-acquired infections
Background:
- Listeriosis is a serious infection caused by Listeria monocytogenes.
- Healthcare facilities are susceptible to hospital-acquired infections, including foodborne illnesses.
- Commercial food preparation equipment can harbor persistent microbial contamination.
Observation:
- A case of hospital-acquired listeriosis was traced to a milkshake machine.
- The machine harbored a Listeria monocytogenes strain linked to a previous contamination event a year prior.
- Despite repeated cleaning and sanitizing, the contamination persisted.
Findings:
- Commercial-grade shake freezer machines can be a source of prolonged Listeria monocytogenes contamination.
- Persistent contamination can occur even with rigorous cleaning protocols.
- Dairy-based products served in healthcare settings may pose a risk to vulnerable patients.
Implications:
- Healthcare facilities need heightened awareness of potential Listeria reservoirs in food service equipment.
- Clinicians should counsel high-risk patients about foods linked to Listeria infections.
- Further research is needed to assess the prevalence of contaminated milkshake machines and associated risks in hospitals.
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