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Recent deaths from Listeriosis were likely caused by smoked salmon. Listeriosis is a rare but serious disease caused by the bacteria Listeria monocytogenes (L. monocytogenes) that can survive and grow on certain high risk foods.

While it may be common for people to eat foods contaminated with a small amount of the bacteria, some people are at risk of becoming sick or dying. The recent victims were over 70 years old and had underlying health conditions which made them more susceptible to the condition. However, Professor Murphy from the Department of Health said:

"This is a timely reminder for people to ensure that food is handled, prepared and stored safely and that those most at-risk of Listeriosis avoid certain foods”.
The department was working with Food Standards Australia and New Zealand, health authorities and food regulators to identify potential sources and mitigate the outbreak.

Listeria infection, or Listeriosis, starts with flu-like symptoms such as fever, chills, muscle aches, nausea, and sometimes diarrhoea. On average, these symptoms start 21 days after eating food contaminated with the bacteria.

Chilled and ready-to-eat seafood, cold meats, soft cheeses and pre-packaged fruits have a higher risk of listeria contamination.

L. monocytogenes is commonly found in the environment (such as soil) and some raw foods. Unlike many other bacteria, L. monocytogenes are unusual because they can grow in the refrigerator. Eating foods that contain L. monocytogenes does not cause illness in most people however some can become sick.

The best way to avoid L. monocytogenes is to eat freshly cooked or freshly prepared food.

Foods that have a higher risk of L. monocytogenes contamination are:

  • chilled seafood such as raw oysters, sashimi and sushi, smoked ready-to-eat seafood and cooked ready-to-eat prawns
  • cold meats from delicatessen counters and sandwich bars, and packaged, sliced ready-to-eat meats
  • cold cooked ready-to-eat chicken (whole, portions, or diced)
  • soft, semi-soft and surface-ripened cheeses such as brie, camembert, ricotta, blue and feta
  • soft serve ice cream

References:  Sydney Morning Herald 24 July 2019
                   The Department of Health

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