Microbial Risk Analysis最新文献

There is a current trend towards plant-based diets in Western countries. Since changes in the diet imply possible changes in exposure to foodborne pathogens, there is an increasing need to assess the microbiological risks associated with these diets. This study aims to assess microbiological risks for French adults associated with Bacillus cereus group III and group IV in hot, homemade cereal- and lentil-based dishes. A probabilistic retail-to-fork risk assessment model was developed considering cooking, cooling at ambient temperature, and storage under chilled conditions. Data came from a representative national survey, public database and literature. The model was developed in R, and uncertainty and variability were separated using second-order Monte Carlo simulations. Not all consumers have the same storage and cooling practices, so the results were expressed by probabilistic distributions built by specific storage time. The mean concentration of Bacillus cereus in portions at the time of consumption after 72 h of storage was 1.2 log CFU.g⁻¹ for cereal-based dishes and 3.4 log CFU.g⁻¹ for lentil-based dishes. After 72 h of storage under chilled conditions, the risk per portion, defined as the probability of contamination over 5 log CFU.g⁻¹, was 0 (95 % CI: 0 - 0) for cereal-based dishes and 7.95 × 10⁻⁴ (95 % CI: 5.55 × 10⁻⁴ - 1.12 × 10⁻³) for lentils-based dishes. However, if cooling time at room temperature reached 24 h, the risk for cereal- and lentil-based dishes increased to 2.39 × 10⁻³ (95 % CI: 1.15 × 10⁻³ - 4.90 × 10⁻³) and 4.66 × 10⁻¹ (95 % CI: 3.16 × 10⁻¹ - 6.07 × 10⁻¹), respectively. The sensitivity analysis indicated that the initial prevalence and level of contamination were key factors in limiting the risk, ranking before cooling time or refrigeration conditions. Besides, the scenario analysis revealed an influence of consumer behaviour regarding cooling and storage time on the risk per portion. The environmental trend towards plant-forward diets, combined with the emerging no-food waste and batch cooking practices in France, will likely favour new consumption patterns and increase the risk associated with Bacillus cereus. Our model will help quantify this extra burden.

This article presents the outcomes of a scientific review and microbiological risk ranking of fresh, frozen, processed, and preserved fruit and vegetables imported into New Zealand. The study was undertaken by New Zealand Food Safety to help in the prioritisation of imported food safety issues for risk management action and ensure that regulatory resources are appropriately focused on food products that represent the highest public health risk.

Risk ranking, also sometimes called comparative risk assessment, is a methodology where the most significant risks associated with specific hazards and foods are identified and characterised, and then compared. The output is a list of pathogen-food combinations ranked according to their relative level of risks, from highest to lowest.

This study involved the development of a New Zealand risk ranking model based on two multicriteria analysis models developed separately by the United States Food and Drug Administration and the European Food Safety Authority (BIOHAZ Panel) for similar risk ranking applications. The New Zealand model uses nine criteria that have been adapted to New Zealand data and circumstances.

The eight top ranking pathogen-produce combinations identified using the New Zealand model were pathogenic E. coli in lettuce, spinach and other leafy greens, Salmonella spp. in lettuce, other leafy greens, tomatoes, melons, and other Cucurbitaceae (e.g. cucumbers, gourds, squashes, pumpkins). Produce categories were also ranked based on overall risk from various pathogens associated with each produce category. The top ranked produce categories, in decreasing order of rank, were: other leafy greens, pods, legumes and grains, tropical fruits, berries, herbs and spinach.

The risk ranking lists provide a starting point and basis for risk management considerations and prioritisation of resources. They will need to be regularly updated to ensure they remain relevant by incorporating the latest epidemiological, hazard, and import volume data. Updates should also consider the availability of new modelling tools and analytical methods for emerging or less common pathogens.

This study assessed the influence of preparing iceberg lettuce salads at home on the risk of Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, and Campylobacter jejuni by conducting quantitative microbial risk assessments (QMRAs¹) for distribution, retail, domestic storage, and cross-contamination. The QMRA simulated pathogen behaviors in lettuce and meat from-farm-to-fork environments. Order of food preparation, hand washing, and lettuce washing were assessed in domestic lettuce salad and raw meat processes. Scenario and sensitivity analyses were performed to compare the importance of the process factors. QMRA simulation revealed that factors related to initial contamination and at-home preparation of foods were more critical than those related to the time-temperature environment during distributions and storages. The risk of L. monocytogenes infection decreased only 1 % even in the absence of cross-contamination. Similarly, the risk of C. jejuni hardly decreased (0.91-fold) even in the absence of lettuce contamination. When the lettuce was not washed, the risk of L. monocytogenes was relatively higher (1.92-fold) than that of other pathogens (E. coli O157:H7,1.44-fold; S. Typhimurium, 1.38-fold; and C. jejuni, 1.36-fold). The risk of E. coli O157:H7 (2.60-fold), S. Typhimurium (2.18-fold), and C. jejuni (2.67-fold) increased when hands were not washed before lettuce preparation, whereas the risk of L. monocytogenes did not increase (1.07-fold). The importance of avoiding cross-contamination through appropriate order of food preparation and hand washing in lettuce salad preparation were quantitatively demonstrated in the present study, which provide essential information for food safety education at home.

We propose a multipathogen Quantitative Microbiological Risk Assessment (QMRA) model to estimate the risk of foodborne illness from bacterial pathogens in raw milk soft cheese. Our work extends an existing QMRA model for pathogenic Shiga toxin-producing Escherichia coli (STEC) (Basak et al.,under review; Perrin et al., 2014) by incorporating the effects of Salmonella and Listeria monocytogenes. This multipathogen model integrates microbial contamination of raw milk at the farm level, as well as the growth and survival of these bacteria during cheese fabrication, ripening, and storage. The public health impact of multipathogen risk associated with raw milk cheese consumption is assessed using Disability-Adjusted Life Years (DALYs). The model evaluates intervention strategies at both pre- and post-harvest stages to estimate intervention costs. Furthermore, it tests various scenarios of these strategies and optimizes intervention parameters to minimize multipathogen risk and associated costs. This article discusses challenges in QMRA model validation, emphasizes model limitations, and explores future perspectives for improvement.

High pathogenicity and low pathogenicity avian influenza (HPAI and LPAI) viruses primarily infect birds, but they can also cause illness in other species, including humans. Some avian influenza (AI) strains can cause fatality rates of over 50 % in human infections. In October 2021, there was a substantial increase in the number of AI infections reported in birds in the UK. Given concerns that more infected and/or contaminated poultry products might reach retail, a risk assessment was performed to ensure that advice relating to the handling and consumption of these products remained appropriate.

The products considered in this risk assessment were commercial chicken and turkey products, farmed duck and geese products, and table eggs. The risk pathway included the likelihood animals or eggs from an infected flock would be sent for further processing, whether the resulting products would be released to retail after inspection, viral persistence during distribution and storage, and the ability of AI viruses to infect humans via the gastrointestinal route. The risk from any AI virus, not just the A(H5N1) strain that began circulating in 2021, was considered. Data was obtained from literature searches and FSA surveys.

The risk assessment determined that the likelihood of human infection with AI from poultry products for the UK population from handling and consuming commercial chicken or turkey products was negligible with low uncertainty, and for farmed duck and geese products was very low with medium uncertainty. The likelihood of infection for people in the UK from handling and consuming hen table eggs was very low with low uncertainty. The uncertainty rankings relate to the differing amounts of data available for each group of poultry products. The severity of illness in humans from AI infection was considered high with medium uncertainty. The conclusions of this risk assessment for UK consumers largely reflected advice and assessments from other countries and previous UK assessments. Given this, current guidance for handling and consuming poultry products was considered appropriate despite the increase in infections in birds during the 2021/22 and 2022/23 avian flu seasons. Since AI viruses were considered generally, these risk characterisations may need to be revisited based on evidence specific to a circulating virus to support risk management decisions.

Aujeszky's disease (AD) is a highly contagious disease of pigs that primarily transmits by respiratory and oral routes. Evidence from recent outbreaks suggests that some swine viruses can survive in contaminated animal feed, thus posing a risk of entry via imports from other countries. To this end, a qualitative risk assessment was undertaken to determine the risk of introduction of AD virus (ADV) and infection of pigs via this route to determine if contaminated animal feed is a viable pathway for the spread of ADV. The feed categories investigated were soya bean/meal/oilcake, pet food, choline/lysine and spray dried porcine plasma. These were chosen based on their use in animal feed and the available data on viral contamination. The overall probability of an animal becoming infected from the importation of feed contaminated with ADV was estimated as Negligible or Very Low for all feed categories. The uncertainty associated with the estimates was assessed as Medium, due to the lack of data around the mechanisms that ADV could contaminate feedstuffs and for infection of susceptible animals from ADV infected feed.

Host-associated fecal indicator measurements can be coupled with quantitative microbial risk assessment to develop risk-based thresholds for recreational use of potential sewage-contaminated waters. These assessments require information on the relative concentrations of indicators and pathogens in discharged sewage, typically based on data collected from wastewater treatment plant influent samples. However, most untreated sewage releases occur from within the collection system itself (i.e. compromised sewer laterals, compromised gravity and force mains, sanitary sewer overflows), where these relationships may differ. This study therefore analyzed the concentrations of a selected reference pathogen (norovirus) and fecal indicator (HF183) in sewage samples from upper and lower segments of gravity sewage collection systems, wastewater pumpstations, and the influent and effluent of treatment plants, to characterize variability in their relative concentrations. Norovirus detection rates were lower and more variable in upper collection system samples due to the smaller population represented; whereas, HF183 was routinely detected at all sites with higher concentrations in the collection system compared to treatment plant influent, resulting in variable comparative relationships across sample locations (types). Mean HF183:NoV ratios ranged from 1.0 × 10⁵ for sewer lateral samples to 7 × 10° for force main samples. Results were used to develop risk-based thresholds for HF183 based on estimated recreational exposure to norovirus following a release from each potential sewage source, with higher thresholds for treatment facility influent compared to forced mains, or effluent. Consequently, this approach can allow for the rapid application of potential risk-based thresholds for recreational water quality applications based on different types of sewage discharge events.

Food safety has benefited from systematic approaches to assess and control risks. The paradigm of risk analysis calls for the components of risk assessment and risk management to be bridged and complemented with risk communication, yet still be separate activities. In practical terms, risk assessment and risk management are, in fact, heavily interdependent upon one another. Collectively, risk assessments, risk management and risk communications are tools or processes that deliver specific outputs. For food safety enhancement, these outputs must be translated into outcomes to yield the desired impacts—improved food safety, human health, and livelihoods. The purpose of this paper to illustrate, using the example of listeriosis, how steps in the risk analysis process used by the Codex Alimentarius Commission's, Codex Committee on Food Hygiene (CCFH), of the and the FAO/WHO Joint Expert Meeting on Microbiological Risk Assessment (JEMRA) align with the various components of the theory change, ultimately leading to impacts on food safety, enhanced health and livelihoods on the global scale.

Dairy farms are vulnerable to the impacts of climate change through the alteration of raw milk quality and pressure on animal health. Measures in dairy farms are necessary to reduce microbiological risks that may impact animal health and may be passed on to humans through the consumption of contaminated dairy products. However, these additional controls should incur lower environmental impact, have a low cost of implementation, minimal impact on milk property, and sufficient effectiveness to control risks. This study selected a dairy farm located under hot weather conditions to demonstrate how these challenges may be considered. Our objective was to present how a multi-criteria decision analysis (MCDA) could be used to select the appropriate mitigation strategy for this farm among fifteen potential food safety measures.

The MCDA framework brought together ten criteria classified into four supra criteria: stakeholder acceptance, food safety effectiveness, environmental impact, and impact on milk properties. The relative performances of various food safety measures scored against the ten criteria were expressed either in qualitative or quantitative values. Ultimately, the outranking MCDA technique, PROMETHEE II, was used to rank the measures.

This study ranked the selected four food safety measures, namely, sand bedding, chitosan supplementation, cooling mister operation, and phage spray, after a series of preselection filters. It was found that none of these dominated the others on the ten criteria. However, MCDA has allowed the determination of the best compromise among the selected measures. It was found that an increase in the frequency of changing the sand bedding ranked first, and an increase in the operation of cooling misters was ranked last.

The study demonstrated the benefit of MCDA in combining criteria of different nature (stakeholder acceptance, food safety effectiveness, environmental impact, milk properties), values, and scales to prioritize food safety measures. The approach can be applied to other dairy farms eager to limit the impacts of climate change while guaranteeing food safety.