An outbreak of gastrointestinal illness and erythema nodosum from grated carrots contaminated with Yersinia pseudotuberculosis

BACKGROUND: Outbreaks of Yersinia pseudotuberculosis infection have been epidemiologically linked to fresh produce, but the bacterium has not been recovered from the food items implicated. In May 2003, a cluster of gastrointestinal illness and erythema nodosum was detected among schoolchildren who had eaten lunches prepared by the same institutional kitchen. METHODS: We conducted a case-control study and trace-back, environmental, and laboratory investigations. Case patients had culture-confirmed Y. pseudotuberculosis O:1 infection, erythema nodosum, or reactive arthritis. Bacterial isolates from clinical and environmental samples were compared using pulsed-field gel electrophoresis (PFGE). RESULTS: Of 7392 persons at risk, 111 (1.5%) met the case definition; 76 case patients and 172 healthy control subjects were enrolled in the case-control study. Only raw grated carrots were significantly associated with illness in a logistic-regression model (multivariable odds ratio, 5.7 [95% confidence interval, 1.7-19.5]); a dose response was found for increasing amount of consumption. Y. pseudotuberculosis O:1 isolates from 39 stool specimens and from 5 (42%) of 12 soil samples that contained carrot residue and were obtained from peeling and washing equipment at the production farm were indistinguishable by PFGE. CONCLUSIONS: Carrots contaminated early in the production process caused a large point-source outbreak. Our findings enable the development of evidence-based strategies to prevent outbreaks of this emerging foodborne pathogen.     

Transport properties of bovine and reindeer beta-lactoglobulin in the Caco-2 cell model

Beta-lactoglobulin (betaLG) is a protein that binds ligands like fatty acids and retinol into the hydrophobic pocket. Our purpose was to study bovine and reindeer betaLG as transporter molecules and compare their transport properties across Caco-2 cell membrane. The reindeer betaLG has more valuable binder characteristics than bovine betaLG because it has only one genetic phenotype and it seems to exhibit better immunological properties. The permeation of betaLG in Caco-2 cells was evaluated by immunoblotting, and the permeation of the model substances retinol, palmitic acid and cholesterol with and without betaLG was determined using [(3)H]-labelled ligands. Both bovine and reindeer betaLG were able to pass across a Caco-2 cell monolayer similarly. Unbound and betaLG-bound [(3)H]retinol and [(3)H]palmitic acid were equally transported across the Caco-2 cell layer, whereas [(3)H]cholesterol could not pass across Caco-2 cells with or without betaLG at any of the studied circumstances. Thus, the bovine and reindeer milk betaLG is not a suitable protein to enhance transport of ligands across the Caco-2 cell membrane, used for predicting intestinal absorption.     

Differences in national legislation for the implementation of lead regulations included in the European directive for the protection of the health and safety of workers with occupational exposure to chemical agents (98/24/EC)

Background The European Council Directive 98/24 on the protection of the health and safety of workers exposed to chemical agents sets out provisions for environmental and biological monitoring, making specific reference to binding limit values and health surveillance measures for those with exposure to lead Objectives To compare how the Directive has been implemented at a national level in EU countries and to determine whether workers receive equivalent protection. Methods Information on selected key issues was collected from 14 EU countries by means of a structured questionnaire. Results National occupational exposure limit values generally reflect that set by the Directive (0.15 mg/m³), but in five cases lower limits are set. National binding biological limit values range from 20 μg/100 ml blood in one country up to 80 μg/100 ml blood in others. The risk to the unborn child is generally recognised with specific measures for women of child-bearing potential or those that are pregnant or breast feeding. In only three countries are special arrangements included for young workers. Limits at which medical surveillance is put into effect are more consistent at 40 μg/100 ml in most countries. The Directive also refers to guidelines for health surveillance but none have been issued with respect to lead. Thus monitoring strategies and requirements for analytical performance vary considerably. Conclusions The results of this survey suggest that protection of workers against the risk of exposure to lead at work is far from uniform across the European Union. Such disparity may also have implications on the requirements set at national level for laboratories measuring lead in blood and/or air. In the interest of harmonisation within the EU, further consideration should be given to the Annex II of the EC Directive 98/24, taking into account the suggestions for lower binding limit values for lead; this should include full guidelines for medical surveillance and requirements for laboratories should be issued. A report from the Members of the Thematic Network: “European Organisers of External Quality Assessment/Proficiency Testing Schemes Related to Occupational and Environmental Laboratory Medicine” with contributions from P. Apostoli, University of Brescia, Italy; J. Macedo, LabMED Center, Porto, Portugal; M. Naray, National Center for Public Health, Budapest, Hungary; D. Adamonienė, Institute of Hygiene, Laboratory of Chemical Hazards Investigation, Lithuania and A. Prokopowicz, Institute of Occupational Medicine and Environmental Health, Sosnowiec, Poland.     

Effect of parental social class, own education and social class on mortality among young men

BACKGROUND: The aim of the study is to examine the effects of parental class, own education and social class on mortality by cause of death among young men. METHODS: The study is based on 1990 census records for 186,408 Finnish men, aged 30-34 in 1990, linked with death records for 1991-95 (1530 deaths). RESULTS: Parental class was associated with all-cause (Index of Relative Dissimilarity (IRD) = 12%) and cause-specific mortality before adjustment for one's own social class and education. Adjustment reduced the IRD by 18-58%, depending on the cause of death, and caused mortality differences to disappear for causes other than cardiovascular diseases and those related to alcohol. The unadjusted variation in all-cause mortality by educational attainment (IRD = 33%) and by own class (IRD = 38%) was greater than by parental class. Adjustment for parental class had only a minor effect on the variation by education and own class. Adjustment for own class reduced the IRD for education in all-cause mortality by 31%, in mortality from disease by 17%, and in mortality from external causes by 33%. For own class the reductions in the IRD obtained by adjustment for education were 36%, 46%, and 33%, respectively. CONCLUSIONS: The effect of parental class on the mortality of young men is indirect and mainly mediated through its influence on education and social class. The effect of education on mortality is as strong as that of occupation-based social class. These variables are not interchangeable measures of socioeconomic status; they both should be taken into account in studies on inequalities in mortality.     

Arginine intake,blood pressure,and the incidence of acute coronary events in men: the Kuopio Ischaemic Heart Disease Risk Factor Study

BACKGROUND: Evidence suggests that dietary supplementation of L-arginine, the precursor of nitric oxide, may protect arteries against atherosclerosis. OBJECTIVE: We tested the hypothesis that dietary arginine intake is associated with a decreased risk of acute coronary events in Finnish men aged 42-60 y. DESIGN: We investigated this association in a prospective cohort study of men who were free of prior coronary artery disease and who were examined in 1984-1989 in the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD). The dietary arginine intake of 1981 men was assessed by a 4-d food intake record during the baseline phase of the KIHD. RESULTS: Men in the highest quintile of dietary arginine intake (>or= 5691 mg/d) did not have a significantly lower risk of acute coronary events than did men in the 4 lower quintiles (relative risk after adjustment for potential coronary risk factors: 1.28; 95% CI: 0.85, 1.94). The covariates were age; examination years; body mass index; systolic blood pressure; serum total, HDL, and LDL cholesterol; serum triacylglycerols; urinary excretion of nicotine metabolites; maximal oxygen uptake in an exercise test; and alcohol intake. Splitting arginine intake into deciles or analyzing plant- and animal-derived arginine separately did not show any association between dietary arginine intake and the risk of acute coronary events. Arginine intake was also not consistently associated with blood pressure. CONCLUSION: Dietary arginine intake is not associated with the risk of acute coronary events in middle-aged men in eastern Finland.     

Change in male and female life expectancy by social class: decomposition by age and cause of death in Finland 1971-95.

STUDY OBJECTIVE: To quantify the contribution of different causes of death and age groups for trends in life expectancy for two major social classes. DESIGN AND SETTING: Prospective study of mortality in Finland among all over 35 year old men and women. Baseline social class (manual/non-manual) was from the 1970, 1975, 1980, 1985 and 1990 census records, and follow up was by computerised record linkage to death certificates for 1971-1995. MAIN RESULTS: From the early 1970s to the early 1990s life expectancy at age 35 increased by about five and four years among Finnish men and women respectively, with largest gains among 55-74 year old men and 65-84 year old women. Life expectancy increase was 5.1 years among non-manual and 3.8 years among manual men; corresponding figures for women were 3.6 and 3.0 years. In the 1980s, when differences in life expectancy increased most rapidly, decline in cardiovascular disease mortality was more rapid in the non-manual than the manual class. Furthermore, increasing mortality for alcohol associated causes, "other diseases", and accidents and violence were most prominent in the manual class. CONCLUSIONS: Explanations of increasing social inequalities in mortality that are based on one underlying factor are difficult to reconcile with the variability in the cause specific trends in social inequalities in mortality. The contribution of older ages to social inequalities in mortality should be more widely recognised.