Victorians planning to feast over the festive period have been warned to take extra care with their food preparation following a spate of poisoning cases including one fatality.
A person has died and six others have fallen ill with listeria in the space of three weeks in a series of cases authorities say aren't linked.
"It is not an outbreak, we don't have a common source of infection," Victoria's chief health officer Charles Guest told reporters on Thursday.
"So it's not as simple as finding the mayonnaise at the church picnic that you can throw out and shut things down."
Health officials haven't found any contaminated foods that could pose a risk to the community or that need be be removed from supermarket shelves.
But with temperatures in excess of 30C expected on Christmas Day the health department is warning people to be extra vigilant with how they prepare and store their meals.
Listeria is a potentially fatal illness caused by bacteria-infested foods that can result in vomiting, diarrhoea and potentially meningitis.
It is particularly serious for children, older people and pregnant women.
The health department won't release specific details about those who've contracted listeria but acknowledge pregnant women and the elderly are among the victims.
Because it's difficult to know if someone has listeria as opposed to another food-poisoning illnesses Professor Guest says it's important to monitor symptoms and seek medical help if they don't dissipate.
"This condition occasionally causes death ... most other types of food poisoning do not cause death," he said.
Health Minister Jill Hennessy has warned Victorians to think about how they transport their food over the Christmas period to avoid bacteria multiplying.
"Think about how you're going to store your food, how you're going to transport things on Christmas Day and of course be wary of leftovers," she said.
Prof Guest says to avoid bacteria growing food should be refrigerated straight after use and not left out until it has cooled down.
TIPS TO AVOID FOOD POISONING AT CHRISTMAS:
* Wash your hands before preparing food
* Wash raw fruit and vegetables well before eating
* Cook all foods of animal origin, including eggs, thoroughly
* Don't use the same boards and knives for cooked foods that you used for raw foods unless they have been washed in warm, soapy water
* Refrigerate food straight after it's been cooked rather than waiting for it to cool down
* Defrost food by placing it on the lower shelves of the fridge or use a microwave.
