Salmonella was responsible for more than half of all foodborne outbreaks in Australia in 2017, according to recently released figures.

A total of 179 foodborne outbreaks were reported in 2017. They affected 2,130 people resulting in at least 290 hospital admissions and five deaths.

Eggs continued to be a source of Salmonella Typhimurium infection across the country, with 49 egg-related outbreaks affecting 746 people with 163 hospitalizations. The largest sickened 119 people.

Campylobacter was the most common pathogen in 2017 with almost 28,500 cases, despite only becoming notifiable in New South Wales in April 2017. A slight decline in the national notification rate was seen in 2017 versus 2016.

The highest rates of infection occurred in children aged 0 to 4 years old. A higher incidence was observed amongst males in every age group when compared with females.

Of six outbreaks with 53 cases, one each was linked to chicken, lamb liver, pâté, and raw milk.

Salmonella and hepatitis A
A slight decline in the Salmonellosis notification rate was observed in 2017 compared with 2015 and 2016. In 2017, 16,416 cases were reported.

Reports were significantly higher in children younger than 5 years old compared with other age groups.

A total of 237 serotypes were identified but Salmonella Typhimurium was the most common with more than 5,900 cases. A total of 851 Salmonella Enteritidis cases were notified. The third was Salmonella Virchow followed by Salmonella Saintpaul.

More than 100 outbreaks were recorded with almost half linked to eggs. Overall, 1,271 people fell sick and 261 were hospitalized.

A dozen people fell sick in a Salmonella Newport outbreak linked to Vietnamese meat rolls. A Salmonella Muenchen outbreak with 20 cases was traced to green turtle meat and a Salmonella Weltevreden roast pork outbreak sickened 36 people at a church.

There were 216 hepatitis A virus cases recorded and 66 hospitalizations but not all these were foodborne.

Eleven cases of HAV, including 10 confirmed and one probable case from the secondary transmission, were part of an outbreak linked to imported frozen mixed berries. Five people were hospitalized.

The mixed berry product, which contained frozen berries imported from two countries, was re-packaged in Australia. HAV was detected in three samples including two sealed packets. The outbreak was linked to a 2015 hepatitis A outbreak with 35 cases, also associated with imported frozen berries.

Listeria and E. coli
All 71 Listeria patients required hospital treatment. The number of people sick is similar to previous years.

Of 22 perinatal cases, 12 were pregnant women and 10 were infants less than four weeks old. There was one miscarriage and six infant deaths. Of 49 other patients, the majority were older than age 65 and 15 were older than 80. Seven people died.

A source was not found in one outbreak with three patients.

Almost 500 cases of Shiga toxin-producing E. coli (STEC) were reported in 2017 with 14 cases of Hemolytic Uremic Syndrome (HUS).

Notifications peaked in children aged 0 to 4, followed by those aged 50 to 59, and were more common in females than males. Most cases were acquired in Australia. Of the 59 known to be infected overseas, India was the most common country.

Consistent with previous years, HUS was mainly reported in children aged less than 5 years old and reports were more common for females compared with males.

Nine Ciguatoxin outbreaks affected 32 people, 11 norovirus incidents sickened 213, and five Clostridium Perfringens outbreaks involved 39 patients. A cryptosporidium outbreak with seven patients was linked to raw milk. The source was unknown for 40 outbreaks with 493 cases.

Restaurants were the most commonly-reported food preparation setting accounting for just over half of all outbreaks and related illnesses.