AbstractSeveral statistical models for salmonella source attribution have been presented in the literature. However, these models have often been found to be sensitive to the model parameterization, as well as the specifics of the data set used. The Bayesian salmonella source attribution model presented here was developed to be generally applicable with small and sparse annual data sets obtained over several years. The full Bayesian model was modularized into three parts (an exposure model, a subtype distribution model, and an epidemiological model) in order to separately estimate unknown parameters in each module. The proposed model takes advantage of the consumption and overall salmonella prevalence of the studied sources, as well as bacteria typing results from adjacent years. The latter were used for a smoothed estimation of the annual relative proportions of different salmonella subtypes in each of the sources. The source‐specific effects and the salmonella subtype‐specific effects were included in the epidemiological model to describe the differences between sources and between subtypes in their ability to infect humans. The estimation of these parameters was based on data from multiple years. Finally, the model combines the total evidence from different modules to proportion human salmonellosis cases according to their sources. The model was applied to allocate reported human salmonellosis cases from the years 2008 to 2015 to eight food sources.
The Finnish salmonella control program (FSCP) for beef production is based on both randomized and selective testing of herds and animals. Sampling of individual animals in abattoirs is randomized. Herds are selectively tested for salmonella on the basis of clinical symptoms and/or other factors. Risk assessment of FSCP is inherently difficult due to the complexity of the complete data set, especially if the detailed labeling of the testing types is lost. However, for a risk assessment of the whole production chain, methods for exploiting all available data should be considered. For this purpose, a hierarchical Bayesian model of true salmonella prevalence was constructed to combine information at different levels of aggregation: herds in geographical regions and individual animals arriving for slaughter. The conditional (municipality specific) probability of selection of a herd for testing was modeled given the underlying true infection status of the herd and information about the general sampling activity in the specific region. The model also accounted for the overall sensitivity of the sampling methods, both at the herd and at the animal level. In 1999, the 95% posterior probability intervals of true salmonella prevalence in the herd population, in individual cattle, and in slaughter animal populations were [0.54%, 1.4%] (mode 0.8%), [0.15%, 0.39%] (mode 0.2%), and [0.12%, 0.36%] (mode 0.2%), respectively. The results will be further exploited in other risk assessments focusing on the subsequent parts of the beef production chain, and in evaluation of the FSCP.
The Finnish Hygiene Passport System, a national legislative requirement, has been used to test the food safety knowledge of food handlers for almost 20 years, resulting in over one million approved hygiene passports. However, information on the relevance of the Hygiene Passport System is virtually nonexistent. In order to evaluate the relevance of the official hygiene passport test, we collected a sample of original official hygiene passport tests from test examiners. We also arranged a simulated hygiene passport test for volunteers without any professional background in the food sector to investigate whether the basic level of hygiene knowledge of Finns is sufficient to pass the test. Our study revealed that more than 80% of the participants in the official hygiene passport test passed. However, participants completing the test in a foreign language or with assistance had significantly more difficulties in passing the test. The results for the simulated test suggested that the food safety knowledge of most Finns would have enabled them to pass the official test without prior training, especially those older than 20 and with a higher educational level. The simulated test also revealed that preparation prior to the test, i.e. study or training, was effective in increasing the food safety knowledge of participants, especially when their knowledge level was initially low, as among young participants. Moreover, significant variation in the difficulty of the test itself was observed, which may affect the pass rate. The current study supports the relevance of the hygiene passport test, showing that without the national requirement for the hygiene passport test, the level of food hygiene knowledge of new employees in the food sector, especially young people aged under 20, would be lower. However, our results suggest that the relevance of the hygiene passport test should be improved by validation of the test and by using official translations when conducting the test in a foreign language. Digitalization of the test would enable the regular evaluation of the test based on accurate data collection. ; Peer reviewed
To promote public health, Finland has adopted a stringent Salmonella control policy. However, the rationale of Salmonella control in pig feeds has been debated after a European Union (EU)-wide cost–benefit analysis, which provided mixed, country-specific results on whether control measures are economically beneficial. The aim of this study was to analyze the costs and benefits of current pig feed Salmonella control in Finland compared to a reduced control scenario. In addition, this study contributes to the literature by looking at the costs across stakeholder groups. The costs of preventive and monitoring measures were assessed, and a Monte Carlo model was developed to simulate costs caused by Salmonella contaminations along the pork supply chain (including feed importation, commercial feed manufacturing, feed transportation, mobile feed mixers, pig farms, slaughterhouses) and because of human salmonellosis originating from contaminated feed. The data were collected from official records and feed sector operators by surveys and interviews. The prevalence of Salmonella was obtained from a previously conducted risk assessment study. The total costs of pig feed Salmonella control were estimated on average to be €4.2–5.4 million per year (95% of simulated years between €2.1 and €9.1 million) for the current control scenario, and €33.8–34.8 million per year (95% €2.2 to €26.0 million) for the reduced control scenario. In the reduced control scenario, the monitoring and prevention costs were decreased down to €1.1–2.1 million, and the costs of Salmonella contaminations and human salmonellosis were up by €32.7 million when compared to the current control scenario. The results suggest that the current pig feed Salmonella control policy of Finland is economically profitable. It can reduce the costs caused by feed-related Salmonella contaminations on average by €29.4 million per year and provides public health benefits. Pig feed Salmonella control can support the effectiveness of the Finnish Salmonella Control Programme. ...
Listeria monocytogenes causes severe consequences especially for persons belonging to risk groups. Finland is among the countries with highest number of listeriosis cases in the European Union. Although most reported cases appear to be sporadic and the maximum bacterial concentration of 100 cfu/g is not usually exceeded at retail, cold smoked and salt-cured fish products have been noted as those products with great risk especially for the elderly. In order to investigate the listeriosis risk more carefully, an exposure assessment was developed, and laboratory results for cold smoked and salt-cured salmon products were exploited. L. monocytogenes exposure was modeled for consumers in two age groups, the elderly population as a risk group and the working-age population as a reference. Incidence was assessed by estimating bacterial growth in the food products at three temperatures. Bayesian estimation of the risk was based on bacterial occurrence and product consumption data and epidemiological population data. The model builds on a two-state Markov chain describing repeated consumption on consecutive days. The cumulative exposure is probabilistically governed by the daily decreasing likelihood of continued consumption and the increasing bacterial concentrations due to growth. The population risk was then predicted with a Poisson distribution accounting for the daily probabilities of purchasing a contaminated product and the cumulative total probability of infection from its use. According to the model presented in this article, elderly Finns are at a greater risk of acquiring listeriosis than healthy adults. The risk for the elderly does not fully diminish even if the products have been stored at the recommended temperature (between 0 and 3 °C). It can be concluded that the stage after retail, i.e. food handling and storage by consumer or professional kitchens, is essential to protection against listeriosis. The estimation model provides means for assessing the joint impacts of these effects.
A Bayesian statistical temporal‐prevalence‐concentration model (TPCM) was built to assess the prevalence and concentration of pathogenic campylobacter species in batches of fresh chicken and turkey meat at retail. The data set was collected from Finnish grocery stores in all the seasons of the year. Observations at low concentration levels are often censored due to the limit of determination of the microbiological methods. This model utilized the potential of Bayesian methods to borrow strength from related samples in order to perform under heavy censoring. In this extreme case the majority of the observed batch‐specific concentrations was below the limit of determination. The hierarchical structure was included in the model in order to take into account the within‐batch and between‐batch variability, which may have a significant impact on the sample outcome depending on the sampling plan. Temporal changes in the prevalence of campylobacter were modeled using a Markovian time series. The proposed model is adaptable for other pathogens if the same type of data set is available. The computation of the model was performed using OpenBUGS software.
Abstract Animal by‐products are whole dead animals, parts of them and products obtained from them that are not used for human consumption. Legislation related to the utilization and disposal of animal by‐products was revised from the beginning of 2023, which limited the disposal of fish‐derived by‐products by burying or delivering them to a landfill in some parts of Finland. The aim of this risk assessment report is to describe the practices followed in remote and non‐remote areas and to assess the possible disease risk to humans and animals arising from the disposal of by‐products from fish and horse slaughtering as well as cutting plants. The risks related to using animal by‐products as carrion were also assessed. At environmentally licensed aquaculture facilities, the delivery of by‐products to processing plant facilities was more common (67%) than at aquaculture facilities inspected based on risk (36%). The annual amounts of by‐products buried or delivered to the landfill were small in the non‐remote area, and slightly higher in the remote area. Horse‐derived by‐products were not produced in remote area slaughterhouses during the period under study. Fish‐derived by‐products from approved food establishments were widely delivered for further processing, most commonly to produce fur animal feed. Disposal of fish‐derived by‐products by burying and delivering to a landfill or as carrion for wild animals was not common. The dangers (pathogens) associated with the burial of fish‐ and horse‐derived by‐products for animals or humans were not considered significant. In carrion use, the spread of pathogens is more likely. The environmental effects of burying by‐products were not part of the mandate, but this should be studied in the future. Setting an annual upper limit for the by‐product to be buried is recommended. The specification of the remote area for fish could also be re‐evaluated.
The project Costs and Risk Assessment of the Health Effects of the Food System employed biological, chemical and nutritional examples to investigate the health and economic risks of food and nutrition in Finland and the cost effectiveness of controls. The project explored the causes and consequences of the health risks associated with food in Finland and sought appropriate risk management measures. The onset of foodborne health hazards can be slow, and therefore even strong efforts to control them at the population level may take years or decades. Based on the project results, several proposals for action were presented, the most important of which are to: 1. deepen and broaden the risk assessment of the public health impact of the food system to compare different health risks, 2. undertake cost–benefit analyses of food control and health care and 3. to study policy instruments for change. Food contributes significantly to the health of the population, which can be influenced by nutrition and food safety. According to the project results, the main burden of disease (BoD) was caused by the inadequate consumption of fruit and vegetables and the excessive intake of salt and saturated fats, resulting in disease burdens of 36,000, 29,000, 32,000 and 9,200 disability-adjusted life years (DALYs)/year, respectively. Reducing the intake of salt and saturated fats in particular would be a cost-effective way to reduce the BoD. Despite the relatively high level of food hygiene achieved in Finland, up to thousands of foodborne infections occur every year, and food contaminants increase the BoD on consumers. Of the biological food hazards, Listeria caused the largest BoD, about 670 DALYs annually. Of the chemical hazards, lead caused the largest BoD, about 570 DALYs annually. Most of the control costs are borne by food businesses. Therefore, the scenarios that most affect businesses also have the greatest financial impact. This publication is part of the implementation of the Government Plan for Analysis, Assessment and ...
Abstract Fish is an important part of nutrition and well‐being. The challenge of Finnish wild fish is contaminants which accumulate in some species in higher concentrations, partially limit the usability of the fish in the food/feed market and weaken the assessment of the state of the marine environment. The aim of this study was to obtain data on the amounts of nutrients and contaminants in domestic fish species that are commercially important or should be increased in use according to national plans. The aim was also to produce information for updating the national fish use recommendations. The concentrations of contaminants in Finnish fish were mostly below the maximum levels set by the EU. The trend of dioxin and PCB compound concentrations in the Baltic Sea has been declining since the 1980s, and the concentrations in Baltic herring appear to have settled around or below the maximum levels in all sea areas and size classes. The PFAS concentrations in the studied fish samples were within the maximum limits, except for Baltic herring in the Archipelago Sea and the Bothnian Sea. Additionally, the PFAS concentrations in Baltic herring rose quite sharply between 2009 and 2023. During the current study, PFAS concentrations in Baltic herring from the same sea area and size classes increased significantly from autumn 2022 to spring 2023. The seasonal trend was suspected to be related to the fish's diet, but factors affecting PFAS concentrations in fish, such as the impact of seasons and fitness (function of weight and size of the fish), need further investigation, and PFAS concentrations in Baltic herring should be monitored. PBDE concentrations in Finnish fish were found to be very low, although they exceeded the environmental quality standard. Mercury concentrations in fish, except for two samples, were lower than the maximum levels set by Commission Regulation (EU) 2023/915. The proportion of methylmercury in total mercury was 56–94% in different fish species. Inorganic arsenic concentrations in all fish samples were below the detection limit of 0.01 mg/kg. The highest concentrations of omega‐3 fatty acids were measured in Baltic herring and vendace. Fish caught from marine areas had higher vitamin D concentrations than those from inland waters, and there was significant variation in concentrations within fish species. With current food consumption and concentration data, the health benefits of fish consumption outweigh the health risks associated with contaminants in fish for all age groups. The greatest health benefits are seen in those over 45 years old, where fish consumption reduces the burden of diseases such as cardiovascular diseases and breast cancer, as well as overall mortality. On a national scale, the current use of domestic and imported fish is estimated to reduce the disease burden annually by nearly 70,000 disability‐adjusted life years (DALYs). As a conclusion, the health benefits of fish consumption outweigh the harms of contaminants in all age groups. Increasing the consumption of fish in accordance with nutritional recommendations would benefit the health of the population. For children and expectant or breastfeeding mothers, a diverse fish consumption is useful. The safe use recommendations of the Finnish Food Authority help this risk group to direct their fish consumption to fishing areas and fish species with the lowest amounts of contaminants.
