Risk assessment of parasites in Norwegian drinking water: opportunities and challenges.

Despite the relative prosperity of Scandinavian countries, contamination of the drinking water supply with parasites has occurred on various occasions in the last few decades. These events have resulted in outbreaks of disease involving several thousand cases and/or the necessity for implementation of boil-water advisories. Against this background, in 2008, and again in 2019, the Norwegian Food Safety Authority requested a risk assessment from an independent scientific body regarding parasites in Norwegian drinking water. On each occasion, it was requested that specific questions were addressed. For the first assessment, data, both of general relevance and specific for Norway, were collected from appropriate sources, as available. Based on some of this information, a quantitative probability model was established and run to estimate the number of cases of waterborne cryptosporidiosis and giardiasis that may be expected in Norway, both in the general public and the immunocompromised, and under conditions where water treatment should be optimal, and also when water treatment efficacy may be compromised by weather conditions. For the second assessment, approximately a decade after the first, an update on the previous assessment was requested. Differences in information availability and other changes between the two assessments were described; although more data were available at the second assessment, considerable gaps still remained. For both assessments, data on the occurrence of these parasites in the Norwegian population, particularly those infected in Norway, were considered a challenge. However, due to changes in reporting requirements in 2020, the situation was improved for the second assessment. In addition, data were lacking for both assessments on whether animals or humans are most likely to contaminate water sources, and the species and genotypes of these parasites in Norwegian animals. It was also noted that some of the newer data on parasite numbers detected in water samples should be treated with caution. Due to this, further modelling was not conducted. The relevance of risk-based sampling rather than ad hoc sampling of water sources was also addressed. Despite the data gaps, this article provides an overview of the opportunities provided by conducting such assessments. In addition, some of the challenges encountered in attempting to estimate the risk posed from parasite contamination of water sources in Norway, particularly under predicted conditions of climate change, are described.

Managing evidence in food safety and nutrition.

Evidence ('data') is at the heart of EFSA's 2020 Strategy and is addressed in three of its operational objectives: (1) adopt an open data approach, (2) improve data interoperability to facilitate data exchange, and (3) migrate towards structured scientific data. As the generation and availability of data have increased exponentially in the last decade, potentially providing a much larger evidence base for risk assessments, it is envisaged that the acquisition and management of evidence to support future food safety risk assessments will be a dominant feature of EFSA's future strategy. During the breakout session on 'Managing evidence' of EFSA's third Scientific Conference 'Science, Food, Society', current challenges and future developments were discussed in evidence management applied to food safety risk assessment, accounting for the increased volume of evidence available as well as the increased IT capabilities to access and analyse it. This paper reports on presentations given and discussions held during the session, which were centred around the following three main topics: (1) (big) data availability and (big) data connection, (2) problem formulation and (3) evidence integration.

Outbreak of Yersinia enterocolitica serogroup O:9 infection and processed pork, Norway.

An outbreak involving 11 persons infected with Yersinia enterocolitica O:9 was investigated in Norway in February 2006. A case-control study and microbiologic investigation indicated a ready-to-eat pork product as the probable source. Appropriate control measures are needed to address consumer risk associated with this product.

[An outbreak of Yersinia enterocolitica O:9-infection]. / Et utbrudd av Yersinia enterocolitica O:9-infeksjon.

BACKGROUND: Yersiniosis is a zoonosis that is transmitted from pigs to humans. In January 2006 more cases of Yersinia enterocolitica enterocolitis than expected were reported in Norway. The fact that the isolates belonged to the O:9 serogroup, which is rare in Norway, and the geographical and temporal clustering of the cases, pointed to an outbreak. We have conducted a retrospective study of 11 patients who were diagnosed during this outbreak. MATERIAL AND METHODS: The material is based upon applicants' information, patient journals and a questionnaire. In order to disclose the source of infection, a case-control survey was performed. RESULTS: Nine of the 11 patients had enterocolitis and two had septicaemia, both of whom died following a few days of treatment. One patient presented with pseudo- appendicitis while another developed monoarthritis, which persisted for more than three months after the debut of symptoms Treatment with antibiotics was offered in six cases. The case-control analysis indicated that brawn was the probable source of infection. INTERPRETATION: This is the first reported Norwegian outbreak of Y. enterocolitica O:9 disease. The incubation time, disease duration and frequency of intestinal and immunological complications corresponds with previously published data. The frequency of septicaemia exceeds several previously reported outbreaks and retrospective studies of sporadic cases.