In the news

Listeria illnesses and a death were reported in Texas, Florida, South Carolina, Pennsylvania, and Maine are linked to Almark Foods hard-boiled eggs. The CDC is concerned that bulk, fresh hard-boiled eggs produced by Almark Foods of Gainesville, Georgia, are contaminated with Listeria and have made people sick. These products were packaged in plastic pails for use nationwide by foodservice operators. The products have not been recalled. However, because Listeria can cause severe infections, the CDC is warning against selling, serving, or using these eggs to make other food products. Seven people infected with the outbreak strain of Listeria monocytogenes have been reported. Four hospitalizations have been reported. One death has been reported from Texas. One illness was reported in a newborn that was infected with Listeria while the mother was pregnant, but the newborn survived.  In this investigation, WGS showed that bacteria isolated from ill people are closely related genetically.  In the PulseNet database, CDC noted two environmental samples from February 2019 that are closely related genetically to bacteria from ill people in this outbreak.  @ https://www.cdc.gov/listeria/outbreaks/eggs-12-19/index.html

Romaine lettuce from the Salinas, California growing region is a likely source of an outbreak of illnesses caused by E. coli O157:H7, according to the FDA and its investigating partners (CDC, and state health authorities). According to the FDA, the data showed that ill people in Maryland were exposed to romaine lettuce harvested in Salinas, California. Additionally, FDA is investigating two other E. coli outbreaks, each caused by strains that are different from each other and different from the larger outbreak. The FDA is investigating two other E. coli outbreaks, each caused by strains that are different from each other and different from the larger outbreak.  One of the additional outbreaks, in Washington state, is linked to romaine lettuce, and the other outbreak, with cases in the U.S. and Canada, is linked to Fresh Express Sunflower Crisp Chopped Salad Kits. As part of these investigations, FDA and state partners are conducting traceback investigations to trace romaine exposures to the source. Currently, the tracebacks on all three outbreaks have identified a common grower in Salinas. FDA, CDC, and California partners are deploying a team to conduct new investigations at several ranches used by this grower as we try to identify the source of the contamination. @ https://www.fda.gov/food/outbreaks-foodborne-illness/investigation-e-coli-o157h7-outbreak-linked-romaine-salinas-california-november-2019?utm_campaign=OutBreak_Romaine_Ecoli_12122019&utm_medium=email&utm_source=Eloqua

Scientists from Cornell University developed a modeling tool to assist the frozen food industry with understanding and managing listeriosis risks. The work was published in J. Food protection (vol 82,12, 2019). A quantitative microbial risk assessment model FFLLoRA (Frozen Food Listeria Lot Risk Assessment) was developed to assess the risk due to L. monocytogenes (LM) contamination in frozen vegetables consumed as a ready-to-eat food. The model was designed to estimate listeriosis risk per serving and the number of illnesses per production lot of frozen vegetables contaminated with LM. Factors evaluated include individual facility factors such as lot size, the prevalence of LM contamination, and consumer handling before consumption. Low-level of LM in frozen vegetables did not result in illnesses. Classification tree analysis emphasized that the initial concentration of LM in the lot, the temperature at which the product is thawed, and whether a serving is cooked as the main predictors for illness from a lot. Overall, the FFLLoRA provides frozen food manufacturers with a tool to assess LM contamination and consumer behavior when managing rare and/or minimal contamination events in frozen foods. More testing increased the probability of finding Listeria contamination. @ https://www.researchgate.net/publication/337382870_An_Assessment_of_Listeriosis_Risk_Associated_with_a_Contaminated_Production_Lot_of_Frozen_Vegetables_Consumed_under_Alternative_Consumer_Handling_Scenarios