Listeria monocytogenes contamination of ready‐to‐eat foods and the risk for human health in the EU

Abstract

Food safety criteria for Listeria monocytogenes in ready-to-eat (RTE) foods have been applied from 2006 onwards (Commission Regulation (EC) 2073/2005. Still, human invasive listeriosis was reported to increase over the period [2009][2010][2011][2012][2013] in the European Union and European Economic Area (EU/EEA). Time series analysis for the 2008-2015 period in the EU/EEA indicated an increasing trend of the monthly notified incidence rate of confirmed human invasive listeriosis of the over 75 age groups and female age group between 25 and 44 years old (probably related to pregnancies). A conceptual model was used to identify factors in the food chain as potential drivers for L. monocytogenes contamination of RTE foods and listeriosis. Factors were related to the host (i. population size of the elderly and/or susceptible people; ii. underlying condition rate), the food (iii. L. monocytogenes prevalence in RTE food at retail; iv. L. monocytogenes concentration in RTE food at retail; v. storage conditions after retail; vi. consumption), the national surveillance systems (vii. improved surveillance), and/or the bacterium (viii. virulence). Factors considered likely to be responsible for the increasing trend in cases are the increased population size of the elderly and susceptible population except for the 25-44 female age group. For the increased incidence rates and cases, the likely factor is the increased proportion of susceptible persons in the age groups over 45 years old for both genders. Quantitative modelling suggests that more than 90% of invasive listeriosis is caused by ingestion of RTE food containing > 2,000 colony forming units (CFU)/g, and that one-third of cases are due to growth in the consumer phase. Awareness should be increased among stakeholders, especially in relation to susceptible risk groups. Innovative methodologies including whole genome sequencing (WGS) for strain identification and monitoring of trends are recommended. Acknowledgements: The Panel wishes to thank the hearing experts: Andrew Hart and Sophie Roussel for the support provided to this scientific output. The Panel also wishes to thank the consortia of the three outsourcing activities under 'Closing gaps for performing a risk assessment on L. monocytogenes in RTE foods' for their collaboration. In addition, R egis Pouillot is thanked for sharing the dose response model as described in Pouillot et al. (2015). Also the epidemiologists and microbiologists of the nominated public health contact points for listeriosis and Listeria isolates in the European Food-and Waterborne Diseases and Zoonoses network (FWD-Net) are thanked for replying to the questionnaire related to the surveillance of listeriosis.

Guidance on the requirements for the development of microbiological criteria

“…For example, in EFSA Panel on Biological Hazards (BIOHAZ) et al. (), the dose–response relationship for L . monocytogenes was derived for 14 age/gender groups, while Pérez‐Rodríguez et al.…”

Establishment of a prototypic Quantitative Microbial Risk Assessment (QMRA) food and feed safety model repository

“…Specifically a thorough work was carried out to modularize the Listeria monocytogenes generic Quantitative Microbiological Risk Assessment (gQMRA) model (EFSA BIOHAZ Panel, 2018). The creation of the models provides a proof-of-concept for the developed framework, to test and improve the information exchange format FSK-ML and to test the open source software tool FSK-Lab.…”

Urgent scientific and technical assistance to provide recommendations for sampling and testing in the processing plants of frozen vegetables aiming at detecting Listeria monocytogenes

“…monocytogenes is widespread in the environment and can be found in soil, water, sewage and decaying vegetation (EFSA BIOHAZ Panel, 2018). monocytogenes is widespread in the environment and can be found in soil, water, sewage and decaying vegetation (EFSA BIOHAZ Panel, 2018).…”

“…This can be done using well-established molecular techniques such as Pulsed-Field Gel Electrophoresis (PFGE), ribotyping, Amplified Fragment Length Polymorphisms (AFLP), Multi-locus Sequence Typing (MLST), PCR methods or other relevant methods including analysis of Whole Genome Sequencing (WGS).WGS techniques, when combined with epidemiological information, have shown the potential to attribute relatedness among L. monocytogenes strains and thus to establish stronger links between human listeriosis cases and causative foods(EFSA BIOHAZ Panel, 2018). This can be done using well-established molecular techniques such as Pulsed-Field Gel Electrophoresis (PFGE), ribotyping, Amplified Fragment Length Polymorphisms (AFLP), Multi-locus Sequence Typing (MLST), PCR methods or other relevant methods including analysis of Whole Genome Sequencing (WGS).WGS techniques, when combined with epidemiological information, have shown the potential to attribute relatedness among L. monocytogenes strains and thus to establish stronger links between human listeriosis cases and causative foods(EFSA BIOHAZ Panel, 2018).…”