Ziektelast van infectieziekten in Europa: een pilot studie

Consequences of different infectious diseases cannot be adequately compared with each other on the basis of the number of patients or mortality data only. It is better to combine all health effects and express the total impact as disease burden, which also takes duration and severity of diseases into account. Information on disease burden also helps to set priorities in European policy for infectious disease control. In a pilot study, the disease burden of seven infectious diseases in Europe has been estimated. In spite of various limitations with regard to availability and quality of data, it was found that HIV infection, tuberculosis and influenza cause, among the selected infectious diseases, the highest disease burden in Europe. Foodborne diseases caused by the bacteria Campylobacter spp., enterohaemorrhagic Escherichia coli and Salmonella spp. and, in particular, measles, are associated with a lower burden. The current disease burden of infectious diseases reflects the balance between the disease threats and the effectiveness of preventive strategies. A low burden stresses the need for the continued support of these strategies, while a high burden indicates the need for additional interventions. Based on this pilot, the RIVM recommends that a full burden of disease study - combining several methods of investigation - be conducted in cooperation with different European institutes.De gevolgen van verschillende infectieziekten zijn onderling niet goed te vergelijken op basis van het aantal patienten of sterftecijfers alleen. Het is beter om alle gezondheidseffecten te combineren en de totale impact uit de drukken in ziektelast, dat ook rekening houdt met duur en ernst van ziekten. Informatie over ziektelast helpt prioriteiten te stellen in het Europese beleid op het gebied van infectieziektenbestrijding. In een pilotstudie is de ziektelast geschat van zeven infectieziekten in Europa. Ondanks verschillende beperkingen in beschikbaarheid en kwaliteit van gegevens wordt geschat dat HIV-infectie, tuberculose en influenza van de geselecteerde infectieziekten de grootste ziektelast in Europa veroorzaken. Voedseloverdraagbare ziekten die worden veroorzaakt door de bacterien Campylobacter spp., enterohemorragische Escherichia coli en Salmonella spp., en mazelen in het bijzonder, zijn geassocieerd met een lagere ziektelast. De huidige ziektelast van de infectieziekten weerspiegelt de balans tussen bedreigingen van de ziekten en effectiviteit van preventiemaatregelen. Een lage ziektelast benadrukt de noodzaak van voortdurende ondersteuning van deze maatregelen, een hoge ziektelast duidt erop dat aanvullende acties nodig zijn. Op basis van deze pilotstudie adviseert het RIVM om samen met verschillende Europese instituten een uitgebreidere studie uit te voeren, die verschillende onderzoeksmethoden combineert

Future challenges to microbial food safety

Despite significant efforts by all parties involved, there is still a considerable burden of foodborne illness, in which micro-organisms play a prominent role. Microbes can enter the food chain at different steps, are highly versatile and can adapt to the environment allowing survival, growth and production of toxic compounds. This sets them apart from chemical agents and thus their study from food toxicology. We summarize the discussions of a conference organized by the Dutch Food and Consumer Products Safety Authority and the European Food Safety Authority. The goal of the conference was to discuss new challenges to food safety that are caused by micro-organisms as well as strategies and methodologies to counter these. Management of food safety is based on generally accepted principles of Hazard Analysis Critical Control Points and of Good Manufacturing Practices. However, a more pro-active, science-based approach is required, starting with the ability to predict where problems might arise by applying the risk analysis framework. Developments that may influence food safety in the future occur on different scales (from global to molecular) and in different time frames (from decades to less than a minute). This necessitates development of new risk assessment approaches, taking the impact of different drivers of change into account. We provide an overview of drivers that may affect food safety and their potential impact on foodborne pathogens and human disease risks. We conclude that many drivers may result in increased food safety risks, requiring active governmental policy setting and anticipation by food industries whereas other drivers may decrease food safety risks. Monitoring of contamination in the food chain, combined with surveillance of human illness and epidemiological investigations of outbreaks and sporadic cases continue to be important sources of information. New approaches in human illness surveillance include the use of molecular markers for improved outbreak detection and source attribution, sero-epidemiology and disease burden estimation. Current developments in molecular techniques make it possible to rapidly assemble information on the genome of various isolates of microbial species of concern. Such information can be used to develop new tracking and tracing methods, and to investigate the behavior of micro-organisms under environmentally relevant stress conditions. These novel tools and insight need to be applied to objectives for food safety strategies, as well as to models that predict microbial behavior. In addition, the increasing complexity of the global food systems necessitates improved communication between all parties involved: scientists, risk assessors and risk managers, as well as consumer

A Quantitative Microbiological Risk Assessment for Salmonella in Pigs for the European Union

A farm‐to‐consumption quantitative microbiological risk assessment (QMRA) for Salmonella in pigs in the European Union has been developed for the European Food Safety Authority. The primary aim of the QMRA was to assess the impact of hypothetical reductions of slaughter‐pig prevalence and the impact of control measures on the risk of human Salmonella infection. A key consideration during the QMRA development was the characterization of variability between E.U. Member States (MSs), and therefore a generic MS model was developed that accounts for differences in pig production, slaughterhouse practices, and consumption patterns. To demonstrate the parameterization of the model, four case study MSs were selected that illustrate the variability in production of pork meat and products across MSs. For the case study MSs the average probability of illness was estimated to be between 1 in 100,000 and 1 in 10 million servings given consumption of one of the three product types considered (pork cuts, minced meat, and fermented ready‐to‐eat sausages). Further analyses of the farm‐to‐consumption QMRA suggest that the vast majority of human risk derives from infected pigs with a high concentration of Salmonella in their feces (≥104 CFU/g). Therefore, it is concluded that interventions should be focused on either decreasing the level of Salmonella in the feces of infected pigs, the introduction of a control step at the abattoir to reduce the transfer of feces to the exterior of the pig, or a control step to reduce the level of Salmonella on the carcass post‐evisceration

Risk ranking of foodborne parasites : state of the art

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Estimating the Costs and the Disease Burden Associated With Campylobacter Infections and Sequelae in the Netherlands

Campylobacter infections pose an important public health problem in the Netherlands. Approximately 79,000 persons per year are estimated to experience symptoms of acute gastroenteritis. Further annually some 1400 ReA cases, 60 GBS cases and 11 IBD cases are associated with a previous Campylobacter infection. Using a stochastic simulation model the disease burden and the cost-of-illness of Campylobacter infections and its sequelae were estimated. Estimates of the Campylobacter-associated disease burden and costs-of-illness were 1185 DALYs (90% C.I. 693 - 1845 DALYs) per year and some 21 million E (90% C.I. 10 - 38 million E) per year respectively.Campylobacter, sequelae, cost-of-illness, disease burden, Netherlands, Food Consumption/Nutrition/Food Safety,

Evaluation of a Performance-Based Expert Elicitation:WHO Global Attribution of Foodborne Diseases

For many societally important science-based decisions, data are inadequate, unreliable or non-existent, and expert advice is sought. In such cases, procedures for eliciting structured expert judgments (SEJ) are increasingly used. This raises questions regarding validity and reproducibility. This paper presents new findings from a large-scale international SEJ study intended to estimate the global burden of foodborne disease on behalf of WHO. The study involved 72 experts distributed over 134 expert panels, with panels comprising thirteen experts on average. Elicitations were conducted in five languages. Performance-based weighted solutions for target questions of interest were formed for each panel. These weights were based on individual expert's statistical accuracy and informativeness, determined using between ten and fifteen calibration variables from the experts' field with known values. Equal weights combinations were also calculated. The main conclusions on expert performance are: (1) SEJ does provide a science-based method for attribution of the global burden of foodborne diseases; (2) equal weighting of experts per panel increased statistical accuracy to acceptable levels, but at the cost of informativeness; (3) performance-based weighting increased informativeness, while retaining accuracy; (4) due to study constraints individual experts' accuracies were generally lower than in other SEJ studies, and (5) there was a negative correlation between experts' informativeness and statistical accuracy which attenuated as accuracy improved, revealing that the least accurate experts drive the negative correlation. It is shown, however, that performance-based weighting has the ability to yield statistically accurate and informative combinations of experts' judgments, thereby offsetting this contrary influence. The present findings suggest that application of SEJ on a large scale is feasible, and motivate the development of enhanced training and tools for remote elicitation of multiple, internationally-dispersed panels

Systematic review of foodborne burden of disease studies: Quality assessment of data and methodology

Burden of disease (BoD) studies aim to identify the public health impact of different health problems and risk factors. To assess BoD, detailed knowledge is needed on epidemiology, disability and mortality in the population under study. This is particularly challenging for foodborne disease, because of the multitude of causative agents and their health effects. The purpose of this study is to systematically review the methodology of foodborne BoD studies. Three key questions were addressed: 1) which data sources and approaches were used to assess mortality, morbidity and disability?, 2) which methodological choices were made to calculate Disability Adjusted Life Years (DALY), and 3) were uncertainty analyses performed and if so, how? Studies (1990-June 2012) in international peer-reviewed journals and grey literature were identified with main inclusion criteria being that the study assessed disability adjusted life years related to foodborne disease. Twenty-four studies met our inclusion criteria. To assess incidence or prevalence of foodborne disease in the population, four approaches could be distinguished, each using a different data source as a starting point, namely 1) laboratory-confirmed cases, 2) cohort or cross-sectional data, 3) syndrome surveillance data and 4) exposure data. Considerable variation existed in BoD methodology (e.g. disability weights, discounting, age-weighting). Almost all studies analyzed the effect of uncertainty as a result of possible imprecision in the parameter values. Awareness of epidemiological and methodological rigor between foodborne BoD studies using the DALY approach is a critical priority for advancing burden of disease studies. Harmonization of methodology that is used and of modeling techniques and high quality data can enlarge the detection of real variation in DALY outcomes between pathogens, between populations or over time. This harmonization can be achieved by identifying substantial data gaps and uncertainty and establish which sequelae of foodborne disease agents should be included in BoD calculations

Библиотековедение как фундаментальная наука

The Netherlands saw an unexplained increase in campylobacteriosis incidence between 2003 and 2011, following a period of continuous decrease. We conducted an ecological study and found a statistical association between campylobacteriosis incidence and the annual number of prescriptions for proton pump inhibitors (PPIs), controlling for the patient's age, fresh and frozen chicken purchases (with or without correction for campylobacter prevalence in fresh poultry meat). The effect of PPIs was larger in the young than in the elderly. However, the counterfactual population-attributable fraction for PPIs was largest for the elderly (ca 45% in 2011) and increased at population level from 8% in 2004 to 27% in 2011. Using the regression model and updated covariate values, we predicted a trend break for 2012, largely due to a decreased number of PPI prescriptions, that was subsequently confirmed by surveillance data. Although causality was not shown, the biological mechanism, age effect and trend-break prediction suggest a substantial impact of PPI use on campylobacteriosis incidence in the Netherlands. We chose the ecological study design to pilot whether it is worthwhile to further pursue the effect of PPI on campylobacteriosis and other gastrointestinal pathogens in prospective cohort studies. We now provide strong arguments to do so

High relative humidity pre-harvest reduces post-harvest proliferation of Salmonella in tomatoes

Outbreaks of human illness caused by enteric pathogens such as Salmonella are increasingly linked to the consumption of fruits and vegetables. Knowledge on the factors affecting Salmonella proliferation on fresh produce therefore becomes increasingly important to safeguard public health. Previous experiments showed a limited impact of pre-harvest production practices on Salmonella proliferation on tomatoes, but suggested a significant effect of harvest time. We explored the data from two previously published and one unpublished experiment using regression trees, which allowed overcoming the interpretational difficulties of classical statistical models with higher order interactions. We assessed the effect of harvest time by explicitly modeling the climatic conditions at harvest time and by performing confirmatory laboratory experiments. Across all datasets, regression trees confirmed the dominant effect of harvest time on Salmonella proliferation, with humidity-related factors emerging as the most important underlying climatic factors. High relative humidity the week prior to harvest was consistently associated with lower Salmonella proliferation. A controlled lab experiment confirmed that tomatoes containing their native epimicrobiota supported significantly lower Salmonella proliferation when incubated at higher humidity prior to inoculation. The complex interactions between environmental conditions and the native microbiota of the tomato crop remain to be fully understood