Listeriosis outbreak likely due to contaminated liver pâté consumed in a tavern, Austria, December 2018

Abstract

In late December 2018, an outbreak of listeriosis occurred after a group of 32 individuals celebrated in a tavern in Styria, Austria; traditional Austrian food (e.g. meat, meat products and cheese) was served. After the celebration, 11 individuals developed gastrointestinal symptoms, including one case with severe sepsis. Cases had consumed mixed platters with several meat products and pâtés originating from a local production facility (company X). Human, food and environmental samples taken from the tavern and company X were tested for L. monocytogenes. Whole genome sequence-based typing detected a novel L. monocytogenes strain of serotype IVb, sequence type 4 and CT7652 in 15 samples; 12 human, two food and one environmental sample from company X with an allelic difference of 0 to 1. Active case finding identified two further cases who had not visited the tavern but tested positive for the outbreak strain. In total, 13 cases (seven females and six males; age range: 4–84 years) were identified. Liver pâté produced by company X was identified as the likely source of the outbreak. Control measures were implemented and since the end of December 2018, no more cases were detected.

Genetic Diversity of Listeria monocytogenes Isolated From Three Commercial Tree Fruit Packinghouses and Evidence of Persistent and Transient Contamination

“…The clones associated with the 2014–2015 multistate listeriosis outbreak linked to caramel apples (i.e., CC1 and ST382) were not found in this study ( Chen et al, 2017c ). Among the clones identified in this study, CC4 was a hypervirulent clone previously associated with multiple listeriosis outbreaks outside United States ( Chen et al, 2016b ; Cabal et al, 2019 ); CC5 had been associated with multiple outbreaks associated with contaminated cheese, ice cream and cantaloupe ( Chen et al, 2016b ); CC554 had been associated with a 2014 multistate outbreak linked to contaminated mung bean sprouts ( Centers for Disease Control and Prevention, 2015 ; Yang et al, 2020 ). The CC4, CC5 and CC554 isolates collected in this study did not match the strains of aforementioned outbreaks (our unpublished data).…”

Backtracking and forward checking of human listeriosis clusters identified a multiclonal outbreak linked to Listeria monocytogenes in meat products of a single producer

“…Strains of at least five of the L. monocytogenes clusters were persistent in the food processing plant and have been detected for nine months to four years. This long period of time may explain the comparatively large allele and SNP distance [12,[41][42][43] between the epidemiologically linked isolates in our study. Furthermore, in three of those clusters, strains were found in both, food and food processing environment, verifying cross-contamination events.…”

Modeling the Growth of Six Listeria monocytogenes Strains in Smoked Salmon Pâté

“…In a survey on the prevalence and contamination levels of L. monocytogenes in pâtés sold in Spain, the pathogen was detected in 5.4% of samples (n = 182), with one sample containing more than 10 2 log CFU/g [ 9 ]. Various listeriosis outbreaks have involved pâté products [ 10 , 11 ]. Recently, L. monocytogenes has been detected in smoked salmon pâté products commercialized by food producing companies from Ireland [ 12 ] and Australia [ 13 ].…”