Everyone’s consumption breaking news
Researchers say people have missed the opportunity to prevent listeriosis from prepackaged sandwiches.
Between 1981 and 2015, eating pre-prepared sandwiches served in hospitals was the most common source of Listeria infection in England and Wales.
The scientists said that despite the guidelines for reducing the risk of listeriosis in the healthcare environment, repeated incidents have shown that no lessons have been learned and the risk factors are similar to those previously described.
Their comments are part of a 2017 study of listeriosis cases related to sandwich eating in a hospital. This incident has also been covered in another report.
After an outbreak of Listeria monocytogenes in the UK in 2019 caused 7 deaths, a review on hospital food was published in 2020. It puts forward five food safety recommendations, including that each trust must appoint an expert and raise the audit standards for high-risk food manufacturers.
The patient ate the company's sandwich a dozen times. In July 2017, Public Health England reported a case of listeriosis in a 53-year-old man from a hospital in Yorkshire and the Humber. Through whole-genome sequencing analysis of Listeria monocytogenes in his blood, it was genetically indistinguishable from the isolate in the sandwich collected in December 2016, which was owned by a company that owns a site in the same area Production. During the hospitalization, the patient ate sandwiches produced by this company 12 times.
Between 2016 and 2020, there were no other cases of Listeria infection in the UK.
According to research published in the Journal of Epidemiology and Infection, contamination of the company's products was discovered during the monitoring of unrelated microorganisms in food, and it was 18 months earlier than the investigation of patients.
The company is an approved manufacturer of sandwiches and salads, and its product offerings include a wide range of products, including the British National Health Service. The company sent an average of 12,600 salads and sandwiches to the healthcare environment every day, but stopped supplying them to the NHS in September 2019 for “commercial” reasons.
Efforts to investigate and control pollution Between 2016 and 2020, more than 3,000 samples of the company's food, ingredients, and environmental swabs were tested. After July 2017, the contamination rate of Listeria monocytogenes dropped from 31% in salads to 0.3%, and the contamination rate of sandwiches dropped from 3% to zero. This pathogen is found in beef, pork, and cheese salads, as well as tuna, eggs, mayonnaise, and chicken sandwiches.
The researchers said the results indicate that the manufacturer's equipment, food contact surfaces and food are continuously contaminated by the Listeria monocytogenes strain.
As part of routine microbiological monitoring, 168 kinds of finished foods produced by the company were collected from two hospitals in 2016. Listeria monocytogenes were isolated from 8 samples, and other Listeria bacteria were isolated from 13 samples, but they were all less than 20 colony forming units per gram (cfu/g).
In December 2016, the local government inspected the company and collected 5 sandwiches. Listeria monocytogenes and Listeria monocytogenes below 20 cfu/g were detected in two egg mayonnaise sandwich samples.
From January to June 2017, samples from the two hospitals found Listeria monocytogenes in 31 of 101 salads tested, and no Listeria monocytogenes was found in 104 sandwiches. Except for a Lorraine quiche salad, which contains 20 cfu/g, all of them are less than 20 cfu/g. In the second half of 2017, the Listeria monocytogenes contamination rate was 26 out of 230 salads and 3 out of 238 sandwiches were positive. In 2018 and 2019, the pollution rate was 11 out of 444, 1 out of 277 in salad, 5 out of 471 in sandwiches, and 5 out of 399.
After the incident and after the implementation of control measures, the Listeria monocytogenes contamination rate in salads and sandwiches collected from hospitals and company factories has declined since July 2017. Between 2017 and 2018, other types of Listeria contamination in hospital food and company sandwiches increased, but decreased in 2019 and 2020.
Water samples from sewer swabs and vegetable washing machines showed that the type of Listeria monocytogenes associated with the infected person was contaminated between July 2017 and July 2019. In August 2017, a second strain of Listeria monocytogenes was detected twice from drained swabs and butter deposits, but it was not recovered from any food or ingredients or other cases of listeriosis in the UK.
Impact of the test decision: Between June 2018 and July 2019, 14 lists of Listeria celesii were recovered from environmental swabs at the production site; four salads from September and October 2017; December 2016 Among the 24 sandwiches between August 2019. The virus was also detected in 94 foods in two hospitals. From October 2019 to December 2019, Listeria monocytogenes was found in the production area, as well as harmless Listeria monocytogenes.
Listeria monocytogenes was not detected in any samples sent by the company to a commercial UKAS ISO 17025 accredited laboratory in the first half of 2017.
Environmental health officials visited the company in July and August 2017 and found that the procedures were adequate, but recently implemented some layout changes to expand the production area. People’s concerns include the disinfection system of the vegetable washing machine, the hand wheel disinfection before moving from a low-risk area to a high-risk area, and the procedure for changing shoes. There is evidence that debris has accumulated in the surface drainage system from low-risk areas to high-risk areas.
Food and environmental samples were collected. Although the company's private laboratory did not detect Listeria monocytogenes, it was detected in York's PHE Food, Water and Environmental Laboratory. According to this study, although it may be due to the sensitivity of the test, the reason for this discrepancy cannot be investigated.
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