FAO/WHO Joint Expert Meeting on Microbiological Risk Assessment (JEMRA): Twenty Years of International Microbiological Risk Assessment.

Since the late 1990s, the Food and Agriculture Organization (FAO) of the United Nations and the World Health Organization (WHO) has convened expert meetings and consultations to address the microbiological risk assessment (MRA). These meetings are held to provide scientific advice in response to requests for from Codex Alimentarius, the international food standard-setting body. Individuals participate in the FAO/WHO joint expert meetings on the microbiological risk assessment (JEMRA) in their personal capacity, as technical experts, yet bring diverse regional and national perspectives that contribute to practical applications, particularly for low- and middle-income countries (LMICs). Over 370 experts from around the globe have contributed to the meeting outcomes that have been published in nearly 40 monographs in the FAO/WHO microbial risk assessment (MRA) series, addressing particular food commodities with microbial hazard(s) combinations or a methodological aspect of microbial risk assessment. FAO/WHO MRA series inform Codex decision-making for the development of international standards for safe food and faire trade in food products; are consulted by risk managers such as food safety authorities and food business operators to make science-based decisions; and are used by academics to advance food safety research and educate the next generation of food safety professionals.

Multistate Outbreak of Listeriosis Associated with Packaged Leafy Green Salads, United States and Canada, 2015-2016.

We investigated an outbreak of listeriosis detected by whole-genome multilocus sequence typing and associated with packaged leafy green salads. Nineteen cases were identified in the United States during July 5, 2015-January 31, 2016; isolates from case-patients were closely related (median difference 3 alleles, range 0-16 alleles). Of 16 case-patients interviewed, all reported salad consumption. Of 9 case-patients who recalled brand information, all reported brands processed at a common US facility. The Public Health Agency of Canada simultaneously investigated 14 cases of listeriosis associated with this outbreak. Isolates from the processing facility, packaged leafy green salads, and 9 case-patients from Canada were closely related to US clinical isolates (median difference 3 alleles, range 0-16 alleles). This investigation led to a recall of packaged leafy green salads made at the processing facility. Additional research is needed to identify best practices and effective policies to reduce the likelihood of Listeria monocytogenes contamination of fresh produce.

Listeria monocytogenes Associated with Pasteurized Chocolate Milk, Ontario, Canada.

In an investigation of a listeriosis outbreak in Ontario, Canada, during November 2015-June 2016, pasteurized chocolate milk was identified as the source. Because listeriosis outbreaks associated with pasteurized milk are rare in North America, these findings highlight that dairy products can be contaminated after pasteurization.

Notes from the Field: Outbreak of Listeriosis Associated with Consumption of Packaged Salad - United States and Canada, 2015-2016.

In September 2015, PulseNet, the national molecular subtyping network for foodborne disease surveillance, identified a cluster of Listeria monocytogenes (Listeria) clinical isolates indistinguishable by two-enzyme pulsed-field gel electrophoresis (PFGE) pattern combination and highly related by whole-genome multilocus sequence typing (wgMLST). A case was defined as isolation of Listeria with the outbreak PFGE pattern and highly related by wgMLST with an isolation date on or after July 5, 2015, the isolate date of the earliest case in this cluster.