An outbreak of gastroenteritis due to Salmonella Typhimurium phage type 170 associated with consumption of a dessert containing raw egg.

Eggs are frequently implicated as a source of foodborne salmonellosis. In February 2009 an investigation was commenced following reports of gastrointestinal illness among diners at a Canberra restaurant. The investigation sought to confirm the existence of an outbreak, identify a source and implement public health measures to prevent more cases. Menus and booking lists were obtained from the restaurant and a case-control study was commenced. A suspected case was defined as a person who ate at the restaurant on 13 or 14 February 2009 and subsequently developed diarrhoea and/or vomiting. Twenty cases and 31 controls were enrolled in the study. Eating a tiramisu dessert containing raw egg had a highly statistically significant association with illness (crude odds ratio 130.50, 95% confidence interval 13.54-1605.28). Among the 20 cases, nine of 12 stool samples were positive for Salmonella Typhimurium phage type 170 (STm 170). No microbiological evidence of STm 170 was obtained from the restaurant or during the egg trace-back investigation. This report highlights the risk associated with consumption of foods containing raw or undercooked shell egg.

Risk factors for sporadic human infection with shiga toxin-producing Escherichia coli in South Australia.

This paper reports the findings from a preliminary study seeking to identify risk factors for sporadic human infection with shiga toxin-producing Escherichia coli (STEC) in South Australia. This phase of the study, conducted between February and September 2002, aimed to make recommendations regarding study methodology, and provided an opportunity to identify any potential risk factors for STEC infections in South Australia. The study design was a prospective age-matched case control study. A case was defined as a person with macroscopic or microscopic evidence of blood in a faecal specimen, and in which a gene associated with the production of shiga toxin (stx 1 or 2) was identified. Two community controls per case were randomly selected from the Social Environmental Risk Context Information System database. Eleven cases and 22 controls were enrolled in the pilot phase of the case control study. Cases were more likely than controls to have eaten berries, including strawberries, blueberries, and blackberries, in the 10 days preceding illness (Mantel Haenszel matched OR 11; 95 per cent CI 1.26-96.12). No other exposures were significantly associated with illness. Due to the small number of study participants, the power of the study was insufficient to expect any significant results. National participation will be vital to obtain sufficient cases in a realistic time, however this would necessitate more consistent ascertainment and reporting of STEC disease between the states and territories.

An outbreak of Campylobacter jejuni infection among conference delegates.

Campylobacter infection is one of the most commonly reported foodborne diseases in Australia however, reported Campylobacter outbreaks are rare. This report describes such an outbreak among delegates attending a 10 day international academic meeting in South Australia during May 2001. A retrospective cohort study of the 29 delegates who attended the conference was conducted. A questionnaire was sent by email with a response rate of 93 per cent. Ten cases (onset of diarrhoea while attending the conference) were identified. Two were culture positive for Campylobacter jejuni. There was a significant association between the illness and eating a number of food items from two restaurants however, environmental investigation of the two venues did not identify a definitive source for the outbreak. This investigation demonstrates the usefulness of email in the distribution of questionnaires among specific cohorts.

An outbreak of infections with a new Salmonella phage type linked to a symptomatic food handler.

In December 2001, the South Australian Communicable Disease Control Branch investigated an outbreak of gastrointestinal illness linked to a Korean style restaurant in metropolitan Adelaide. Twenty-eight people were identified as having experienced gastrointestinal symptoms subsequent to dining at the restaurant between 9 and 12 December 2001. A case-control study implicated mango pudding dessert (OR 16.67 95% CI 2.03-177.04) and plain chicken (OR 10.67 95% CI 1.04-264.32). Nineteen cases and one food handler submitted faecal specimens that grew Salmonella Typhimurium 64var. Two samples of mango pudding and one sample of pickled Chinese cabbage also grew Salmonella Typhimurium 64var. The infected food handler reported an onset of illness 2 days before cases first reported eating at the restaurant. The food handler's only role was to prepare the mango pudding dessert in an area external to the restaurant's kitchen. Illness was strongly associated with consumption of a contaminated mango pudding dessert, with contamination most likely resulting from the symptomatic and culture positive food handler who prepared the dish. This outbreak demonstrates the importance of excluding symptomatic food handlers, and the need for appropriately informing and educating food handlers regarding safe food handling procedures. Restaurants with staff and management from non-English speaking backgrounds should be specifically targeted for education that is both culturally sensitive and language specific.