Expert Elicitation for Estimation of the Proportion Foodborne for Selected Microbial Pathogens in New Zealand.

Objectives: To estimate the proportions of human cases of nine specific microbial diseases in New Zealand that were due to transmission by food and the proportion of the foodborne burden that was due to transmission by some specific foods. Materials and Methods: Subjective probability distributions were elicited from 10 food safety experts using a modified Delphi approach. In addition to uniform weighting of experts' opinions, two techniques were used to measure individual's expertise; self-assessment and performance-based weighting using Cooke's classical method. Aggregate estimates were derived by simulation. Results: Food was estimated to be the primary route of transmission for infections due to Campylobacter spp., Listeria monocytogenes, nontyphoid Salmonella spp., Vibrio parahaemolyticus, and Yersinia enterocolitica. Uncertainties were lowest for organisms where the self-assessed expertise level was highest. Conclusions: Foodborne proportion estimates were more "polarized" than for a similar elicitation in 2005. That is, where food was the primary transmission route the estimated proportion on account of food was higher (62.1-90.6% in the current study for self-assessed expertise weighted estimates, compared to 56.2-89.2% in 2005); where food was not the primary transmission route the estimated proportion because of food was lower (27.6-34.0% in the current study compared to 31.5-39.5% in 2005). These estimates represent an essential resource for determining the burden of foodborne disease in New Zealand.

Predictive modelling of interventions to improve iodine intake in New Zealand.

OBJECTIVE: The potential effects of four interventions to improve iodine intakes of six New Zealand population groups are assessed. DESIGN: A model was developed to estimate iodine intake when (i) bread is manufactured with or without iodized salt, (ii) recommended foods are consumed to augment iodine intake, (iii) iodine supplementation as recommended for pregnant women is taken and (iv) the level of iodization for use in bread manufacture is doubled from 25-65 mg to 100 mg iodine/kg salt. SETTING: New Zealanders have low and decreasing iodine intakes and low iodine status. Predictive modelling is a useful tool to assess the likely impact, and potential risk, of nutrition interventions. SUBJECTS: Food consumption information was sourced from 24 h diet recall records for 4576 New Zealanders aged over 5 years. RESULTS: Most consumers (73-100 %) are predicted to achieve an adequate iodine intake when salt iodized at 25-65 mg iodine/kg salt is used in bread manufacture, except in pregnant females of whom 37 % are likely to meet the estimated average requirement. Current dietary advice to achieve estimated average requirements is challenging for some consumers. Pregnant women are predicted to achieve adequate but not excessive iodine intakes when 150 µg of supplemental iodine is taken daily, assuming iodized salt in bread. CONCLUSIONS: The manufacture of bread with iodized salt and supplemental iodine for pregnant women are predicted to be effective interventions to lift iodine intakes in New Zealand. Current estimations of iodine intake will be improved with information on discretionary salt and supplemental iodine usage.

Risk ranking for foodborne microbial hazards in New Zealand: burden of disease estimates.

Priority setting for food safety management at a national level requires risks to be ranked according to defined criteria. In this study, two approaches (disability-adjusted life years (DALYs) and cost of illness (COI)) were used to generate estimates of the burden of disease for certain potentially foodborne diseases (campylobacteriosis, salmonellosis, listeriosis (invasive, perinatal, and nonperinatal), infection with Shiga toxin-producing Escherichia coli (STEC), yersiniosis, and norovirus infection) and their sequelae in New Zealand. A modified Delphi approach was used to estimate the food-attributable proportion for these diseases. The two approaches gave a similar ranking for the selected diseases, with campylobacteriosis and its sequelae accounting for the greatest proportion of the overall burden of disease by far.

Ranking the risk of pesticide dietary intake.

Pesticide residues in various foods were assessed for the relative risk to the consumer. The analysis took into account criteria such as a pesticide's toxicity, usage, frequency of occurrence in foods, frequency of Maximum Residue Level (MRL) exceedances, and the overall risks of specific pesticide/food combinations. Examination of the top ten ranked pesticides for each criterion showed that there are no trends of commonality. Thus, no single pesticide is of particular concern from a consumer's point of view. This suggests that the consumer's risk perception is likely to be higher than justified.

Dietary exposure to xenoestrogens in New Zealand.

Continuing evidence of the feminising effects of xenoestrogens on a range of wildlife species increases the need to assess the human health risk of these estrogen mimics. We have estimated the exposure of New Zealand males, females and young men to a range of naturally occurring and synthetic xenoestrogens found in food. Only estrogenic compounds that act by interaction with the estrogen receptor have been included. Theoretical plasma estrogen activity levels were derived from estrogen exposure estimates and estrogenic potency data. Theoretical plasma levels were compared with published data for specific xenoestrogens. There was surprisingly close agreement. Xenoestrogenicity from dietary intake was almost equally attributed to naturally occurring and synthetic xenoestrogens. Relative contributions for a male, for example were isoflavones (genistein and daidzein) (36%) and bisphenol A (34%) with smaller contributions from alkyl phenols (18%) and the flavonoids (phloretin and kaempferol) (12%). It is suggested that dietary xenoestrogens might have a pharmacological effect on New Zealand males and postmenopausal women, but are unlikely to be significant for pre-menopausal women.