Fresh produce-associated foodborne disease outbreaks in Australia, 2001 to 2017

Fresh produce is an important source of foodborne outbreaks in Australia. Using descriptive analysis, we examined confirmed and suspected foodborne outbreaks associated with fresh produce in Australia recorded in the OzFoodNet outbreak register from 2001 to 2017. The outbreak register contains reports of foodborne disease outbreaks collected by OzFoodNet epidemiologists and public health officials. A fresh produce outbreak was defined as the occurrence of two or more cases of the same illness in which the investigation had implicated a common food and this food contained fresh produce. A total of 92 fresh produce outbreaks were reported, encompassing 3,422 reported illnesses, 446 hospitalisations and four deaths. Of these outbreaks, 76.1% (70/92) were caused by a known pathogen, with the majority caused by either Salmonella enterica (n = 30) or Norovirus (n = 29). Most outbreaks (77.2%; 71/92) were associated with consumption of foods containing multiple ingredients, some of which were not fresh produce. The largest outbreaks associated with a single fresh produce item included bean sprouts contaminated with S. enterica serovar Saintpaul (419 illnesses and 76 hospitalisations) and semi-dried tomatoes contaminated with Hepatitis A (372 illnesses and 169 hospitalisations). Restaurants (45.7%; n = 42/92) and commercial catering (15.2%: n = 14/92) were common settings for fresh produce outbreaks. Outbreaks occurred in all states and territories of Australia and in all seasons, with an increased frequency in the warmer months (September-May). Although the number of fresh produce-associated outbreaks did not seem to be increasing in Australia, integrated surveillance is needed to rapidly identify sources of infection due to the propensity of these outbreaks to be large and widespread.