Ozfoodnet Quarterly Report, 1 October To 31 December 2015 The Ozfoodnet Working Group

The Australian Government Department of Health established the OzFoodNet network in 2000 to collaborate nationally to investigate foodborne disease. In each Australian state and territory, OzFoodNet epidemiologists investigate outbreaks of enteric infection. In addition, OzFoodNet conducts studies on the burden of illness and coordinates national investigations into outbreaks of foodborne disease. This quarterly report documents investigations of outbreaks of gastrointestinal illness and clusters of disease potentially related to food, which commenced in Australia between 1 October and 31 December 2015. Data were received from OzFoodNet epidemiologists in all Australian states and territories. The data in this report are provisional and subject to change. During the 4th quarter of 2015 (1 October to 31 December), OzFoodNet sites reported 585 outbreaks of enteric illness, including those transmitted by contaminated food or water. Outbreaks of gastroenteritis are often not reported to health authorities, which results in current figures under-representing the true burden of enteric disease outbreaks within Australia. There were 10,184 people affected in these outbreaks and 240 hospitalisations. There were 22 deaths reported during these outbreaks. This represents an increase in the number of people affected compared with the 5-year average from 2010 to 2014 for the 4th quarter (n=9,077). The majority of reported outbreaks of gastrointestinal illness in Australia are due to person-to-person transmission. In this quarter, 80% (469/585) of outbreaks were transmitted via this route (see Table 1). This percentage was similar to the same quarter in 2014 (78%, 469/601). The total number and the proportion is also similar to the 5-year average (4th quarter, 2010-2014) of 409 outbreaks (79%, 409/518) outbreaks transmitted person-to-person. Of the person-to-person outbreaks in the 4th quarter of 2015, 46% (216/469) occurred in child care facilities and 41% (193/469) occurred in aged care facilities.