Outbreak results reported at ECDC conference

Experts have shared findings from Cryptosporidium, Listeria, Trichinella, and Salmonella outbreaks at an event in Europe.

Among presentations at the European Scientific Conference on Applied Infectious Disease Epidemiology (ESCAIDE) was one about the Danish perspective on two multi-country outbreaks. These included a Salmonella outbreak linked to chicken meat from Poland and Listeria in fish from a Danish producer.

The meeting organized by the European Centre for Disease Prevention and Control (ECDC) also discussed a July 2023 botulism outbreak linked to potato omelets (tortilla de patata) eaten in Spain. Italy and Norway had two cases of people who had been to Spain. Potential contamination pathways remain unknown.

Large outbreaks of Cryptosporidium linked to lamb contact events in England were highlighted. One incident affected almost 800 people.

In recent years, working farms that are ordinarily closed to the public have invited visitors during the lambing season. They are not subject to the same oversight as farms permanently open to the public. Scientists assessed the public health burden and findings of three large Cryptosporidium parvum outbreaks linked to lambing events on working farms in England in 2023 and 2024.

The events offered lamb contact and feeding, receiving 2,400 and more than 8,000 visitors. Cryptosporidium cases in the three outbreaks were 264, 482, and 775, with microbiological and epidemiological evidence for transmission from lambs. The cases were mainly of women aged 18 to 49 and children younger than 16. Across two outbreaks, 42 percent of cases reported seeking healthcare, and 75 people were hospitalized. Visitors described cuddling and feeding lambs. In the first outbreak, a lamb fecal sample was positive, and the samples were matched with those from patients.

Environmental investigators found inadequate infection prevention and control practices, including concerns regarding handwashing facilities, animal health, animal handling and feeding, and staff preparedness. Food was also served in or close to where animals were being handled.

Listeria in Germany
In March 2023, in eight days, Listeria monocytogenes was isolated twice from blood and once from the pleural fluid of three patients on synthetic glucocorticoids at one hospital in Germany. They were aged between 55 and 90, and two people died.

Sequencing showed all three isolates were related. Food supply records suggested sliced scalded sausage as the likely source, and Listeria monocytogenes isolated from four retained packaged sliced sausage and ham samples matched patient isolates.

Bacterial counts in all samples were below the legal limit of 100 CFU/gram for Listeria before the end of the shelf life in ready-to-eat foods. Researchers said that a universal 100 CFU/gram threshold is insufficient to protect high-risk groups. They advocated for greater caution in the supply, preparation, and consumption of deli meats in German hospitals and recommended the development of dietary recommendations. 

Trichinella in Lebanon
In November and December 2023, 147 suspected trichinellosis cases were identified in Jahliyeh, Lebanon, and 43 people were hospitalized. The age range of cases was 2 to 82 and 59 percent were female.

Almost all people reported buying meat from a local butcher shop, with 126 consuming beef or lamb but abstaining from pork and 18 eating pork. Also, 60 consumed uncooked meat, while 71 ate it fried or barbecued. An inspection of the butchers revealed inadequate hygiene practices and improper meat storage. Both ground and beef sausage samples contained Trichinella. 

An investigation suggested that contaminated beef was the vehicle of infection. The butcher shop likely mixed pork with other types of meat. 

Salmonella in Malta
In August 2023, two hospitalized cases of Extended-spectrum beta-lactamase (ESBL) producing Salmonella Kentucky were reported from the same locality in Malta.

Food history identified the consumption of eggs from the same farm. In the traceback investigations, five farms that supply this site were identified. Human isolates clustered with each other and were related to a sample from a laying hen from one of the supply farms that tested positive for ESBL-producing Salmonella Kentucky.

Several issues at the farm were identified, including antibiotic misuse and improper separation of flocks regardless of age. No culling or targeted measures were implemented as, in EU and Maltese legislation, Salmonella Kentucky is not a target species.

“We recommend adapting existing local and EU legislations to include relevant Salmonella strains or multidrug-resistant bacteria to prevent foodborne zoonotic transmission of these pathogens,” said scientists.

Long-term E. coli problems
Finally, researchers have described long-term complications experienced up to three decades after E. coli O157 and E. coli-associated hemolytic uremic syndrome (HUS) in Wales.

Scientists compared complications in individuals at least one year after E. coli O157 or HUS to general population comparators. The exposed were residents in Wales registered at a General Practitioner (GP) practice with laboratory-confirmed E. coli O157 and a specimen date between January 1990 and 2019. Complications were categorized as renal, neurological, cardiac, gastrointestinal, or respiratory and as mild, severe, or either.

The team identified 1,245 individuals with E. coli O157 infections, 53 of whom developed HUS. The most common complications were renal, respiratory, gastrointestinal, and cardiac.

“Long-term complications were identified in up to one in three people after STEC O157 and HUS. We recommend that individuals exposed to STEC be monitored for late-emerging complications,” they said.

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Source: https://www.foodsafetynews.com/2024/11/outbreak-results-reported-at-ecdc-conference/