Listeriosis Risk Model for Cancer Patients Who Consume Ready-to-Eat Salad.

The foodborne pathogen Listeria monocytogenes generally infects immunocompromised individuals, such as cancer patients, more frequently and with higher morbidity and mortality than the general population. Because of the anticipated risk associated with L. monocytogenes and other pathogens in produce, immunocompromised individuals are often placed on neutropenic diets that exclude fresh produce, though these risks have not been quantified. Therefore, this study developed a data-driven risk model for listeriosis in cancer patients who consume ready-to-eat (RTE) salads, consisting of leafy greens, cucumbers, and tomatoes, as influenced by kitchen-scale treatments and storage practices. Monte Carlo simulations were used to model the risk of invasive listeriosis during one chemotherapy cycle. Refrigerating all salad components decreased the median risk by approximately one-half log. For refrigerated salads with no treatment, the predicted median risk was ≤ 4.3 × 10-08. When salad ingredients were surface blanched with greens rinsed, the predicted risk decreased to 5.4 × 10-10. Predicted risk was lowest (1.4 × 10-13) for a blanched "salad" consisting of solely cucumbers and tomatoes. Interestingly, rinsing, as recommended by FDA, only decreased the median risk by 1 log. A sensitivity analysis revealed that the highly variable dose-response parameter k strongly influenced risk, indicating that reducing uncertainty in this variable may improve model accuracy. Overall, this study demonstrates that kitchen-scale pathogen reduction approaches have high risk reduction efficacy and could be considered as an alternative to diets that exclude produce when making risk management decisions.

Kitchen-Scale Treatments for Reduction of Listeria monocytogenes in Prepared Produce.

ABSTRACT: Listeriosis, a foodborne illness caused by Listeria monocytogenes, has relatively low incidence, but a substantial mortality rate, particularly in immunocompromised populations. Because of the known risk of L. monocytogenes and other pathogens in produce, immunocompromised individuals are often placed on neutropenic diets that exclude fresh produce. Therefore, this study aimed to evaluate several kitchen-scale treatments as potential interventions to reduce L. monocytogenes in prepared produce. Cucumbers, apples, and celery were dip inoculated with a three-strain cocktail of L. monocytogenes and dried for 24 h. Inoculated products were subjected to the following treatments as applicable: commercial sanitizer soak (90 s, with agitation), tap water rinse (15 s), tap water soak (90 s, with agitation), surface blanching (25 s), tap water rinse (15 s) followed by peeling, and surface blanching (25 s) followed by peeling. In addition, inoculum uptake in celery and the impact of two types of peelers (mechanical crank and manual) were assessed. Treated samples were plated on differential media and incubated for 48 h at 37°C. L. monocytogenes populations were then enumerated and compared with the untreated control (in log CFUs per gram). All treatments lacked efficacy for celery, with reductions significantly less (P < 0.05) than in other products, likely because of inoculum internalization. The sanitizer soak, tap water rinse, and tap water soak did not differ in efficacy (P > 0.05), which was low for cucumbers (<1.5 log CFU/g), apples (<1.3 log CFU/g), and celery (<0.7 log CFU/g). The two types of apple peelers did not differ in efficacy (P > 0.05). Surface blanching and surface blanching followed by peeling were the most effective treatments for both cucumbers and apples (P < 0.05), with average reductions of 4.2 to 5.1 and 3.5 to 5.9 log CFU/g, respectively.

Monetizing the Impact of Food Safety Recalls on the Low-Moisture Food Industry.

ABSTRACT: New Food Safety and Modernization Act rules require that food producers implement and validate processes that sufficiently reduce the risk of known hazards, such as those posed by microbial pathogens. Investments in food safety technology choices are ultimately business decisions, and current decision-making methods make it difficult to quantify financial value associated with food safety risk reduction. Predicted financial loss is a tangible way to quantify how a recall might affect the manufacturer. The hypothesis of this study was that class I recalls of low-moisture foods due to the presence of microbial pathogens have a significant negative economic impact on the affected manufacturers, which can be quantified in terms of loss in market capitalization. Financial impacts of the recalls were analyzed over a 10-year period by computing the cumulative abnormal return (CAR) in stock values over a recall event period for 22 low-moisture foods made by publicly held companies. Abnormal returns were aggregated over an event window (0 to 20 days) to compute the CAR, which was multiplied by prerecall market capitalization to compute monetary losses due to the recall event. The CARs for a 20-day postrecall period were -26.5 to 8.4%, with a mean of -5.1%. These CARs translated to a median loss in corporate value due to a recall of $243 million for the recall events analyzed in this study. If implementation of a food safety technology could reduce risk of a recall by fivefold, the mean annual economic benefit would be >$2 million in reduced risk for companies such as those included in the study. Such analyses can positively impact business decisions to invest in food safety technologies.