Foodborne outbreaks affected more than 2,000 and killed nine people in Australia in 2012, according to the latest OzFoodNet annual report.
OzFoodNet sites reported 144 outbreaks of foodborne and suspected foodborne illness involving 2,117 people with 183 hospitalized. The largest number of outbreaks, 47, was recorded by New South Wales.
One of every five outbreaks was due to Salmonella Typhimurium. Other frequent pathogens were norovirus, other Salmonella serovars, scombrotoxin, Campylobacter species and Clostridium perfringens.
Restaurants were the most often reported food preparation setting – 71 of the 144 outbreaks followed by private residences with 18 outbreaks.
A single food vehicle was identified for 60 outbreaks and 30 others were attributed to multiple food vehicles. Of the outbreaks attributed to a single food vehicle 28 were associated with eating dishes containing raw or minimally cooked eggs and 27 were due to Salmonella Typhimurium with the other due to Salmonella 4,5,12:i:- (commonly known as monophasic Salmonella Typhimurium).
In Australia, around 4.1 million domestically acquired cases of foodborne gastroenteritis occur each year, costing an estimated $1.2 billion Australian dollars (US$900 million) annually.
The government established OzFoodNet, Australia’s foodborne disease surveillance system, in 2000. It analyses national level information on the incidence of diseases caused by pathogens commonly transmitted by food, and investigates foodborne disease outbreaks.
When asked why the 2012 annual report had only just been published, a spokesman for the Australian Government’s Department of Health told Food Safety News that such reports are not intended as a mechanism for real-time notification to the public of food products implicated in outbreaks.
“Annual and quarterly reports provide an epidemiological snapshot of activity during the reporting period and a view of long term trends. This work is undertaken through Commonwealth and jurisdictional health and food regulation authorities, with whom OzFoodNet works closely,” he said.
“In addition to the quarterly and annual OzFoodNet Reports, the Australian Government Department of Health makes data available on disease potentially transmitted by food in Australia in multiple, more timely, forms including through the National Notifiable Disease Surveillance System (NNDSS).”
The latest quarterly OzFoodNet report that has been published is from January to March 2015.
For every case of salmonellosis notified to a health department there are an estimated seven infections in the community, while there are eight cases in the community for every notified case of Shiga toxin-producing E. coli (STEC) and 10 infections for every notified case of campylobacteriosis.
OzFoodNet sites reported 27,976 notifications of nine diseases or conditions that may be transmitted by food. This is a 9 percent decrease compared with a mean of 30,747 notifications per year for 2007-2011.
Campylobacter and Salmonella
The most commonly notified infections in 2012 were Campylobacter with 15,668 notifications, followed by Salmonella with 11,249 alerts. Almost 11,000 Salmonella notifications were further typed into 157 unique serovars.
Overall, 54 percent of notified Campylobacter cases were males. Notification rates were highest in children 0 to 4 years old for both males and females.
The median age for salmonellosis notifications was 25, similar to 24 years in 2011. The highest rates were in children 0 to 4 years old for males and females. The ratio of male to female cases was equal.
During 2012, OzFoodNet sites reported 827 cases of Salmonella Enteritidis infection compared with 812 notifications in 2011 and 835 in 2010.
Listeria and STEC
There were 93 notifications of Listeria monocytogenes in 2012 higher than the five-year historical mean. Thirty were in people 60 years of age or over and females accounted for 61 percent.
In 2012, there were 112 notifications of STEC infection, a rate equivalent to the five-year historical mean and 20 cases were also diagnosed with haemolytic uraemic syndrome (HUS). Just over half (59/112) of cases were male and the median age was 46 (range 1 to 95 years). For those with HUS, 14 were male and six female and the median age was 13 (range 1 to 87 years).
Serogroup information was available for 56 percent of STEC cases. The most common identified were: O157 (30 of 63); O26 (eight); O113 (five) and O111 (three).
There were 546 notifications of Shigella infection in 2012. It is estimated around 12 percent of shigellosis cases are acquired via foodborne transmission. Notification rates were highest in males and females 0 to 4 years. Travel history was available for 371 of the 546 alerts and 54 percent acquired illness overseas.
In 2012, there were 166 hepatitis A notifications. The median age of cases was 27 years (range 1 to 92 years) and 51 percent were female.
OzFoodNet said the data can assist agencies to document sources of foodborne disease, develop food safety policies and prevent foodborne illness.
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