Background information
In response to the request from Codex for scientific advice, FAO and WHO has undertaken the risk assessment on L. monocytogenes in several foods since 1999. The 2004 FAO/WHO risk assessment on L. monocytogenes (MRA4 and MRA5)1,2 provided scientific insight into the risk characterization of L. monocytogenes contamination in food and the seriousness of listeriosis for susceptible populations. These risk assessment documents covered a cross-section of RTE foods (pasteurized milk, ice cream, cold-smoked fish and fermented meats) linked to invasive listeriosis. Since the publication of these documents, outbreaks of listeriosis continue to occur across the globe associated with previously reported foods, but also with many previously unreported food vehicles, including fresh and minimally processed fruits and vegetables. In 2020, a virtual meeting of the Joint FAO/WHO Expert Meeting on Microbiological Risk Assessment (JEMRA) of L. monocytogenes in RTE Food: Attribution, Characterization and Monitoring was held to review recent data on L. monocytogenes and determine the need to modify, update, or develop new risk assessment models and tools for this pathogen3. The expert group recommended to extend future risk assessments to diverse commodity sub-groups and to consider a farm-to-fork risk assessment. The expert group also recommended that future risk assessments should review groupings of susceptible populations based on physiological risks and other socio-economic factors. In conclusion, the expert group identified several critical gaps in the current FAO/WHO risk assessment model and collectively agreed that updating the model would be valuable for informing risk analysis strategies, including in low- and middle-income countries (LMICs).
The summary of the 2020 expert meeting was reported to the 52nd session of the Codex Committee on Food Hygiene (CCFH52) in March 2022, and the proposal that JEMRA undertake a full farm-to-table risk assessment on L. monocytogenes in foods was supported by the members of CCFH524,5. Based on the request of CCFH52, FAO and WHO hosted a meeting last October 2022 and elaborated formal models for the risk assessment for Listeria monocytogenes for leafy greens, cantaloupe, frozen vegetables and ready-to-eat fish.
Scope and objectives of the meeting
The purpose of the meeting is to test and revise the full farm-to-table risk assessment for Listeria monocytogenes in foods.
The assessment will include the following types of food:
- Leafy greens
- Cantaloupe melon
- Frozen vegetables (for example peas, corn)
- RTE seafood that allows for the growth of L. monocytogenes, for example, gravad (sugar-salt marinated) and smoked salmon.
Based on the risk assessment outputs, this expert meeting will inform a possible future revision of the Guidelines on the Application of General Principles of Food Hygiene to the Control of Listeria monocytogenes in Foods (CXG 61-2007).6
1 MRA4
2 MRA5
3 Summary report
4 Matters Arising from the Work of FAO and WHO (including JEMRA)
5 The report of CCFH52
6 CXG 61-2007