Longueuil, Canada
Longueuil, Canada

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Chen Y.,Grocery Manufacturers Association | Ross W.H.,Food Directorate | Whiting R.C.,Exponent, Inc. | van Stelten A.,Colorado State University | And 4 more authors.
Applied and Environmental Microbiology | Year: 2011

Internalin A (InlA; encoded by inlA) facilitates the crossing of the intestinal barrier by Listeria monocytogenes. Mutations leading to a premature stop codon (PMSC) in inlA and thus attenuated mammalian virulence have been reported. We recently characterized 502 L. monocytogenes food isolates from a retail survey and 507 human clinical isolates from multiple U.S. states with respect to the presence/absence of inlA mutations. The objective of this study was to investigate the hypothesis that dose responses for human listeriosis vary between L. monocytogenes strains with and those without a PMSC in inlA. Subtype-specific prevalence and concentration distributions in food, along with epidemiologic and consumption data, were input into established doseresponse models to generate an r value (probability of a cell causing illness). Under the conservative assumption that L. monocytogenes levels at retail represent levels consumed, mean log10 r values were -8.1 and -10.7 for L. monocytogenes subtypes with genes encoding a full-length and a truncated InlA, respectively. L. monocytogenes carrying a 5' frameshift mutation in a homopolymeric tract showed a mean log10 r value of -12.1. Confidence intervals for the r values and their differences varied depending on subtypes. When the increase in concentration of L. monocytogenes subtypes between retail and consumption was considered, mean log10 r values were reduced to -10.4, -13.8, and -12.8 for the subtypes with genes encoding a full-length InlA, for the subtypes carrying a PMSC in inlA, and for all L. monocytogenes isolates regardless of subtype, respectively. Our study provides further quantitative evidence that L. monocytogenes subtypes vary in abilities and relative likelihoods of causing human disease, which were mechanistically related to defined genetic markers. © 2011, American Society for Microbiology.


Zarkadas M.,Canadian Celiac Association | Dubois S.,Food Directorate | Macisaac K.,Canadian Celiac Association | Cantin I.,Canadian Celiac Association | And 7 more authors.
Journal of Human Nutrition and Dietetics | Year: 2013

Objective: Strict adherence to a gluten-free diet is the only treatment for coeliac disease. The gluten-free diet is complex, costly and impacts on all activities involving food, making it difficult to maintain for a lifetime. The purpose of this cross-sectional study was to evaluate the difficulties experienced, the strategies used and the emotional impact of following a gluten-free diet among Canadians with coeliac disease. Methods: A questionnaire was mailed to all members (n = 10 693) of both the Canadian Celiac Association and the Fondation québécoise de la maladie coœliaque in 2008. Results: The overall response rate was 72%. Results are presented for the 5912 respondents (≥18 years) reporting biopsy-confirmed coeliac disease and/or dermatitis herpetiformis. Two-thirds never intentionally consumed gluten. Women reported significantly greater emotional responses to a gluten-free diet but, with time, were more accepting of it than men. Difficulties and negative emotions were experienced less frequently by those on the diet for >5 years, although food labelling and eating away from home remained very problematic. Frustration and isolation because of the diet were the most common negative emotions experienced. Conclusions: The present study quantifies the difficulties experienced, the strategies used and the emotional impact of following a gluten-free diet. It highlights the need to improve the training and education of dietitians, other health providers and the food service industry workers about coeliac disease and a gluten-free diet, with the aim of better helping individuals improve their adherence to a gluten-free diet and their quality of life. © 2012 Canadian Celiac Association and Food Directorate Health Canada Journal of Human Nutrition and Dietetics © 2012 The British Dietetic Association Ltd.


PubMed | University of Calgary, McGill University, University of Manitoba, Montreal Childrens Hospital and 2 more.
Type: Clinical Trial | Journal: The Journal of allergy and clinical immunology | Year: 2016

The diagnosis of anaphylaxis currently relies on suggestive clinical history after exposure to a potential triggering factor because no reliable diagnostic marker is available to confirm the diagnosis.We aimed to evaluate tryptase levels in children with anaphylaxis and to examine predictors of elevated tryptase level (defined as 11.4 g/L during reaction and for those with a baseline level, defined as a reaction level of at least 2 ng/mL + 1.2 [postreaction tryptase level]).Children presenting with anaphylaxis to the Montreal Childrens Hospital were recruited over a 4-year period. Symptoms, triggers, and management of anaphylaxis were documented. Levels during the reaction and approximately 9 months after the reaction were compared on the basis of paired means using the t distribution. Multivariate linear and logistic regressions were used to evaluate the association between tryptase levels and risk factors.Over a 4-year period, 203 children had serum tryptase levels measured. Among these, 39 children (19.2%; 95% CI, 14.1%-25.4%) had elevated levels. Only severe reactions were associated with reaction levels of 11.4 g/L or more (odds ratio, 6.5; 95% CI, 2.2-19.0). Milk-induced anaphylaxis and severe reactions were more likely associated with increased tryptase levels (beta-adjusted, 4.0; 95% CI, 0.95-7.0, and 7.5; 95% CI, 4.8-10.3, respectively). Reaction levels exceeding the threshold level of 2 ng/mL + 1.2 (postreaction tryptase level) detected most of the anaphylactic reactions, particularly if baseline levels were taken within 2 months of the reaction.Tryptase levels are particularly useful for the diagnosis of severe and/or milk-induced anaphylaxis. Assessing the difference between reaction and postreaction tryptase levels may improve diagnostic sensitivity.


PubMed | Health Analysis Division, Office of Nutrition Policy and Promotion and Food Directorate
Type: Journal Article | Journal: Health reports | Year: 2016

Although vitamin C is not produced in the body, it is important for many biochemical and physiological functions. Little is known about the current vitamin C status of Canadians. This study describes the correlates of vitamin C status in a nationally representative sample of adults.Data are from the 2012/2013 Canadian Health Measures Survey. Plasma vitamin C (L-ascorbic acid) concentrations were measured among a fasting subsample of respondents aged 20 to 79 (n = 1,615). Vitamin C status, prevalence of deficiency (plasma vitamin C < 11 mol/L), and use of vitamin C-containing supplements were estimated. Multivariate regression models were used to examine associations between vitamin C status and sociodemographic characteristics, smoking, body mass index, supplement use, and consumption of fruit juice and citrus fruit.The mean plasma vitamin C concentration of adults aged 20 to 79 was 53 mol/L; fewer than 3% were vitamin C-deficient. Almost 22% took a vitamin C-containing supplement. Concentrations were lower among smokers and people who were obese, and higher among vitamin C supplement users and fruit juice and citrus fruit consumers. Multivariate models showed that supplement use was the strongest and most consistent predictor of vitamin C status; fruit juice and citrus fruit consumption were predictors only among populations with lower vitamin C concentrations (for example, smokers, obese).Few Canadians were vitamin C-deficient. Smokers and people with a higher BMI were most at risk of lower vitamin C concentrations; concentrations were higher among supplement users and consumers of fruit juice and citrus fruit.


Ben-Shoshan M.,McGill University | Harrington D.W.,McMaster University | Soller L.,McGill University | Fragapane J.,McGill University | And 5 more authors.
Journal of Allergy and Clinical Immunology | Year: 2010

Background: Recent studies suggest an increased prevalence of food-induced allergy and an increased incidence of food-related anaphylaxis. However, prevalence estimates of food allergies vary considerably between studies. Objectives: To determine the prevalence of peanut, tree nut, fish, shellfish, and sesame allergy in Canada. Methods: Using comparable methodology to Sicherer et al in the United States in 2002, we performed a cross-Canada, random telephone survey. Food allergy was defined as perceived (based on self-report), probable (based on convincing history or self-report of physician diagnosis), or confirmed (based on history and evidence of confirmatory tests). Results: Of 10,596 households surveyed in 2008 and 2009, 3666 responded (34.6% participation rate), of which 3613 completed the entire interview, representing 9667 individuals. The prevalence of perceived peanut allergy was 1.00% (95% CI, 0.80%-1.20%); tree nut, 1.22% (95% CI, 1.00%-1.44%); fish, 0.51% (95% CI, 0.37%-0.65%); shellfish, 1.60% (95% CI, 1.35%-1.86%); and sesame, 0.10% (95% CI, 0.04%-0.17%). The prevalence of probable allergy was 0.93% (95% CI, 0.74%-1.12%); 1.14% (95% CI, 0.92%-1.35%); 0.48% (95% CI, 0.34%-0.61%); 1.42% (95% CI, 1.18%-1.66%); and 0.09% (95% CI, 0.03%-0.15%), respectively. Because of the infrequency of confirmatory tests and the difficulty in obtaining results if performed, the prevalence of confirmed allergy was much lower. Conclusion: This is the first nationwide Canadian study to determine the prevalence of severe food allergies. Our results indicate disparities between perceived and confirmed food allergy that might contribute to the wide range of published prevalence estimates. © 2010 American Academy of Allergy, Asthma & Immunology.


Soller L.,McGill University | Ben-Shoshan M.,McGill University | Harrington D.W.,Queen's University | Knoll M.,McGill University | And 8 more authors.
Journal of Allergy and Clinical Immunology: In Practice | Year: 2015

Background: Studies suggest that individuals of low education and/or income, new Canadians (immigrated <10 years ago), and individuals of Aboriginal identity may have fewer food allergies than the general population. However, given the difficulty in recruiting such populations (hereafter referred to as vulnerable populations), by using conventional survey methodologies, the prevalence of food allergy among these populations in Canada has not been estimated. Objectives: To estimate the prevalence of food allergy among vulnerable populations in Canada, to compare with the nonvulnerable populations and to identify demographic characteristics predictive of food allergy. Methods: By using 2006 Canadian Census data, postal codes with high proportions of vulnerable populations were identified and households were randomly selected to participate in a telephone survey. Information on food allergies and demographics was collected. Prevalence estimates were weighted by using Census data to account for the targeted sampling. Multivariable logistic regression was used to identify predictors of food allergy. Results: Of 12,762 eligible households contacted, 5734 households completed the questionnaire (45% response rate). Food allergy was less common among adults without postsecondary education versus those with postsecondary education (6.4% [95% CI, 5.5%-7.3%] vs 8.9% [95% CI, 7.7%-10%]) and new Canadians versus those born in Canada (3.2% [95% CI, 2.2%-4.3%] vs 8.2% [95% CI, 7.4%-9.1%]). There was no difference in prevalence between those of low and of high income or those with and without Aboriginal identity. Conclusion: Analysis of our data suggests that individuals of low education and new Canadians self-report fewer allergies, which may be due to genetics, environment, lack of appropriate health care, or lack of awareness of allergies, which reduces self-report. © 2014 American Academy of Allergy, Asthma & Immunology.


Borucki Castro S.I.,Agriculture and Agri Food Canada | Berthiaume R.,Agriculture and Agri Food Canada | Robichaud A.,Food Directorate | Lacasse P.,Agriculture and Agri Food Canada
Journal of Dairy Science | Year: 2012

Two studies were conducted to determine the effects of dietary iodine and teat-dipping practices on iodine concentrations in milk. In the first study, 63 cows in mid lactation were assigned to a 3 × 3 factorial design in which the main effects were dietary iodine levels (0.3, 0.6, and 0.9. mg of dietary I/kg of dry matter) and 3 different postdip managements (chlorhexidine with dip cup, 1% iodine dip cup, and 1% iodine by manual spray). During the 13-d pre-experimental period and the 15-d experimental period, noniodized sanitizers were used in premilking management. During the pre-experimental period, the levels of milk iodine averaged 241.2 ± 5.8 μg/kg, and no relationship was found with lactation number, days in milk, or milk production. Milk iodine concentrations increased linearly with iodine intake. Although teat dipping with 1% iodine had no effect on milk iodine concentration, the same solution applied by spraying greatly increased milk iodine levels. The second study was conducted to determine the effects of udder preparation before milking on milk iodine concentrations. Thirty-two lactating cows were assigned to 4 treatments: no predip (Con); predip with a predip solution containing 0.5% iodine. +. complete cleaning (Comp); predip with a postdip solution containing 1% iodine. +. complete cleaning (Post); and predip with a predip solution containing 0.5% iodine. +. incomplete cleaning (Inc). During the 14-d pre-experimental period and the 19-d experimental period, cows were fed the same diet, and noniodized sanitizers were used for postmilking dipping. During the last week of treatment, milk iodine averaged 164, 189, 218, and 252 ± 9.8 μg/kg for Con, Comp, Post, and Inc, respectively. Preplanned orthogonal contrasts indicated that predipping with a 0.5% iodine predip solution completely wiped off (Comp) tended to increase milk iodine content above that of the control and that the iodine content of Post and Inc were higher than that of the Comp treatment. The results of the first experiment confirm that, to preserve milk safety, iodine should not be fed above requirements. Spraying iodine-based teat-dipping solutions results in large increases in milk iodine content and should be avoided. Predipping teats with an iodine-based sanitizer is an acceptable practice, but must be performed with the appropriate product and completely wiped off before milking. © 2012 American Dairy Science Association.


Cao X.-L.,Food Directorate | Zhang J.,Food Directorate | Zhang J.,Chinese Institute of Urban Environment | Goodyer C.G.,McGill University | And 3 more authors.
Chemosphere | Year: 2012

In this study, the presence of bisphenol A (BPA) in human placental and fetal liver samples collected from 1998 to 2008 was investigated to provide a more detailed analysis of the transfer of BPA across the placenta and fetal exposure to BPA. The average concentrations in placental samples were 12.6ngg-1 for free BPA, 17.2ngg-1 for BPA-glu, and 30.2ngg-1 for total BPA. The highest concentrations in placental samples were 165ngg-1 for free BPA, 178ngg-1 for BPA-glu, and 280ngg-1 for total BPA. Samples with higher levels of BPA-glu had higher levels of free BPA in general. Fetal age was observed to have a significant effect on BPA-glu levels in placental samples, but not on free or total BPA. The percentages of free BPA relative to total BPA for the placental samples varied considerably from 4.2% to 100%, suggesting that the ability of maternal liver and/or the placenta to conjugate BPA is highly variable during early to mid-gestation. The average concentrations in fetal liver samples were 9.02ngg-1 for free BPA, 19.1ngg-1 for BPA-glu, and 25.8ngg-1 for total BPA. The highest concentrations in fetal liver samples were 37.7ngg-1 for free BPA, 93.9ngg-1 for BPA-glu, and 123ngg-1 for total BPA. The percentages of free BPA level relative to total BPA for all fetal liver samples varied from 12.4% to 99.1%, indicating extensive variability in the ability of the human feto-placental unit to glucuronidate BPA. © 2012.


PubMed | University of British Columbia, University of Calgary, Montreal Childrens Hospital, Food Directorate and McGill University
Type: | Journal: Journal of asthma and allergy | Year: 2017

There are no data on the percentage of visits due to anaphylaxis in the emergency department (ED), triggers, and management of anaphylaxis across different provinces in Canada.To compare the percentage of anaphylaxis cases among all ED visits, as well as the triggers and management of anaphylaxis between two Canadian pediatric EDs (PEDs).As part of the Cross-Canada Anaphylaxis Registry (C-CARE), children presenting to the British Columbia Childrens Hospital (BCCH) and Montreal Childrens Hospital (MCH) EDs with anaphylaxis were recruited. Characteristics, triggers, and management of anaphylaxis were documented using a standardized data entry form. Differences in demographics, triggers, and management were determined by comparing the difference of proportions and 95% confidence interval.Between June 2014 and June 2016, there were 346 visits due to anaphylaxis among 93,730 PED visits at the BCCH ED and 631 anaphylaxis visits among 164,669 pediatric visits at the MCH ED. In both centers, the majority of cases were triggered by food (BCCH 91.3% [88.7, 94.0], MCH 82.4% [79.7, 85.3]), of which peanuts were the most common culprit (24.7% [20.9, 29.9] and 19.0% [15.8, 22.7], respectively). Pre-hospital administration of epinephrine (BCCH 27.7% [23.2, 32.8], MCH 33.1% [29.5, 37.0]) and antihistamines (BCCH 50.6% [45.2, 56.0], MCH 47.1% [43.1, 51.0]) was similar. In-hospital management differed in terms of increased epinephrine, antihistamine, and steroid use at the BCCH (59.2% [53.9, 64.4], 59.8% [54.4, 65.0], and 60.1% [54.7, 65.3], respectively) compared to the MCH (42.2% [38.3, 46.2], 36.2% [32.5, 40.1], and 11.9% [9.5, 14.8], respectively). Despite differences in management, percentage of cases admitted to the intensive care unit was similar between the two centers.Compared to previous European and North American reports, there is a high percentage of anaphylaxis cases in two PEDs across Canada with substantial differences in hospital management practices. It is crucial to develop training programs that aim to increase epinephrine use in anaphylaxis.


PubMed | Memorial University of Newfoundland, McGill University, University of Calgary, Food Directorate and 2 more.
Type: | Journal: The Journal of pediatrics | Year: 2016

To determine the recurrence rate of anaphylaxis in children medically attended in an emergency department (ED), we performed a prospective cohort study to evaluate prehospital and ED management of children with recurrent anaphylaxis and to assess factors associated with recurrent anaphylaxis.As part of the Cross-Canada Anaphylaxis Registry, parents of children with anaphylaxis identified prospectively in 3 EDs and through an emergency medical response service were contacted annually after presentation and queried on subsequent reactions. Cox regression analysis determined factors associated with recurrence.Among 292 children who were registered as having had medical attended anaphylaxis, 68.5% completed annual follow-up questionnaires. Forty-seven patients experienced 65 episodes of anaphylaxis during 369 patient-years of follow-up. Food was the trigger in 84.6% of cases, and epinephrine was used in 66.2%. In 50.8%, epinephrine was used outside the health care facility, and 81.7% were brought to a health care facility for treatment. Asthma, reaction triggered by food, and use of epinephrine during the index episode increased the odds of recurrent reaction. Patients whose initial reaction was triggered by peanut were less likely to have a recurrent reaction.We report a yearly anaphylaxis recurrence rate of 17.6% in children. There is substantial underuse of epinephrine in cases of anaphylaxis. Educational programs that promote effective avoidance strategies and prompt use of epinephrine are required.

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