In June 2015, an outbreak of salmonellosis occurred among people who had eaten at a restaurant in Darwin, Northern Territory, Australia over 2 consecutive nights.
We conducted a retrospective cohort study of diners who ate at the restaurant on 19 and 20 June 2015. Diners were telephoned and a questionnaire recorded symptoms and menu items consumed. An outbreak case was defined as anyone with laboratory confirmed Salmonella Typhimurium PT9 (STm9) or a clinically compatible illness after eating at the restaurant.
Environmental health officers inspected the premises and collected food samples. We contacted 79/83 of the cohort (response rate 95%); 21 were cases (attack rate 27%), and 9 had laboratory confirmed STm9 infection. The most commonly reported symptoms were diarrhoea (100%), abdominal pain (95%), fever (95%) and nausea (95%). Fifteen people sought medical attention and 7 presented to hospital.
The outbreak was most likely caused by consumption of duck prosciutto, which was consumed by all cases (OR 18.6, CI 3.0–∞, P<0.01) and was prepared on site.
Salmonella was not detected in any food samples but a standard plate count of 2×107 col- ony forming units per gram on samples of duck prosciutto demonstrated bacterial contamination. The restaurant used inappropriate methodology for curing the duck prosciutto. Restaurants should consider purchasing pre-made cured meats, or if preparing them on site, ensure that they adhere to safe methods of production.
An outbreak of salmonellosis associated with duck prosciutto at a Northern Territory restaurant
CDI, vol 41, no 1, 2017, Anthony DK Draper, Claire N Morton, Joshua NI Heath, Justin A Lim, Anninka I Schiek, Stephanie Davis, Vicki L Krause, Peter G Markey
Commun Dis Intell 2017;41(1):E16 – E20.