Food warning ahead of Christmas

One person has died and six others have been hospitalised from listeria poisoning just days before Christmas.

With temperatures in excess of 30C expected on Christmas Day, the health department is warning people to be extra vigilant in the way they prepare and store their meals.

"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."

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.