Hygiene and health risks associated with the consumption of edible lamellibranch molluscs.

Edible lamellibranch molluscs are frequently the cause of very serious outbreaks of food poisoning. Microbiological suitability for human consumption, according to EC Reg. n. 1441/2007, is only based on two faecal bacteriological contamination parameters (Escherichia coli and Salmonella) and does not consider other microorganisms which are naturally present within the marine environment and are potentially pathogenic such as those belonging to the genus Vibrio. In this study, a total of 540 samples of edible lamellibranch molluscs (mussels, clams and oysters) bred in Sardinia were analyzed for E. coli and Salmonella, according to EC Reg n. 1441/2005, and for the presence of Vibrios of major public health interest. Environmental parameters (seawater temperature and salinity) were also recorded. The 40% (n=216) of samples were positive for Vibrio while the levels of E. coli were above the legal European limit only in 6.4% of samples. A correlation between the presence of micro-organisms of faecal origin and potentially harmful Vibrios to human health was not observed. Vibrio alginolyticus was the most common in 68% of isolated species, followed by Vibrio parahaemolyticus in 22.6%, Vibrio cholerae in 6% and Vibrio vulnificus in 1.1%. Virulence gene (trh sequence) was present in 1.6% of the V. parahaemolyticus-positive samples. The V. cholerae, V. vulnificus and V. alginolyticus strains detected were non toxigenic. The absence of genes encoding major virulence factors in the studied strains does not exclude the possibility of exposure to pathogenic strains. This study indicates the potential health risk associated with the presence of pathogenic Vibrios in edible lamellibranch molluscs bred in Sardinia, where shellfish production is very important to the local economy.

Evaluation of the level of domestic hygiene in household kitchens.

BACKGROUND: Each year in industrialized countries, 30-40% or more cases of food poisoning occur in the household. The aims of this study are to describe the aspects related to food safety in households by carrying out a microbiological characterization of the kitchens in residential dwellings and to increase consumers' awareness concerning the importance of good hygienic practices, which are required for preventing foodborne diseases at household level. METHODS: The collection of data involved taking 760 analytical samples of kitchen-counter tops and food from 80 kitchens of private dwellings; the manner in which food was treated was evaluated from the moment of purchase to its transformation and storage by means of a checklist; the questionnaire enabled us to determine the extent of consumers' knowledge concerning the food sector. RESULTS: Overall, the results showed a good level of hygiene concerning both food and kitchen-counter top food surfaces. The respondents of the questionnaire did not appear to be aware of various health risks especially concerning the management of the temperature and compartments of refrigerators as well as food storage times and the cooking or heating of food. CONCLUSIONS: The data indicate that final consumers should take more care when cleaning kitchen-counter tops and washing salad; special training programmes should be included in school curricular in order to increase citizens' awareness and knowledge concerning food risks within the household.