A woman has died and thousands of people are at risk of Listeria infection after the bacteria was detected in food from I Cook Foods, a south-east Melbourne catering company which supplies food to hospitals, aged care homes and Meals on Wheels.
The catering service has been shut down after the woman, who was in her 80s, died in Knox Private Hospital on February 4. According to a health department spokesperson, the woman contracted a Listeria-related illness while in hospital being treated for an unrelated condition in late January.
Six positive samples of Listeria were discovered at the company’s Dandenong South kitchen during an investigation into the cause of the woman’s death.
Dr. Brett Sutton, Victoria’s acting Chief Health Officer (CHO), said that people who have eaten the contaminated food might still develop illness, as the incubation period can be as long as 90 days. “Potentially thousands of people have been exposed,” said Sutton.
He also said the health department is taking the necessary steps to ensure I Cook Foods passes all tests before re-opening — a process that could take weeks — but was reluctant to lay the blame on the company until an investigation is carried out.
About listeria
Listeria is a bacterium that infects humans through contaminated food. There are many strains of Listeria, but only one, Listeria monocytogenes, is known to cause food-borne illness (called listeriosis). Listeria enters the body through the gastrointestinal tract, and once inside the body it can travel through the bloodstream and into the central nervous system.
Listeria is rare, but it can be extremely dangerous — particularly to pregnant women, unborn children, the elderly and immunocompromised people. Pregnant women are about 20 times more likely to contract listeriosis than other healthy adults, and it can result in miscarriage or stillbirth. People with HIV/AIDS are 300 times more likely to get ill than those with a healthy immune system.
Listeria is most commonly found in deli and other cold meats, pre-packaged salad, soft cheese, unpasteurised dairy products, soft-serve ice cream, fruits, pâté and chilled seafood.
Symptoms of listeriosis usually present within one to two weeks, but can vary between a few days and up to 90 days. Symptoms may include:
- fever
- muscle pains
- nausea
- diarrhoea
- headache
- stiffness
- confusion
- loss of balance
- convulsions
Last year, six people died and one woman miscarried after a Listeria outbreak linked to rockmelon grown in New South Wales. There have been two cases of listeriosis in Victoria in 2019 compared to nine in the same period last year, with 27 in total in 2018.
Preventing listeria
The challenges of controlling Listeria are considerable given its high resistance to common food preservative methods (including salt, smoke and acidics), and its ability to survive and grow at refrigeration temperatures (around 5°C).
All sectors of the food chain must implement controls and apply food safety best practices to manage the food safety hazards, including Listeria, that could cause a food-borne illness outbreak. Prevention is the best defence, and well-trained, informed Food Handlers are a critical part of it.
To learn more about Listeria, visit A Lesson In Listeria – Everything You Need To Know published by the Australian Institute of Food Safety.