Listeria linked to rockmelons has claimed five lives in Australia, but the true extent of the outbreak may not be known for some time.
Victoria's deputy chief health officer on Friday confirmed the fifth victim, an elderly man who died from the infection earlier in March.
"This latest case - the death of a man in his 80s - has only just been linked to the outbreak as a result of our microbiological testing," Dr Brett Sutton said.
Two earlier Victorian deaths have been linked to the outbreak, as have two in Sydney.
The NSW victims were identified as a man and a woman both aged over 65 with underlying medical conditions.
A miscarriage in Victoria was also linked to the outbreak, and a total 19 people - including those who died - had been affected across the country.
Food Safety Information Council spokeswoman Lydia Buchtmann said listeria was unusual, because it could take up to 90 days to produce symptoms.
"We would expect to see more cases linked to the rockmelon," she told AAP.
"If you are concerned, if you have been unwell, if you have eaten rockmelon and you are worried, go and see your GP."
Rombola Family Farms at Nericon near Griffith in the NSW Riverina voluntarily halted production of potentially contaminated melon types after becoming aware of the outbreak.
All affected produce has been withdrawn from sale and distribution.
Information to date indicates all people affected in Victoria ate rockmelon before the national recall.
Rockmelons currently available for sale are not affected.
The bacterial infection is particularly dangerous for pregnant women, their unborn babies and elderly people. It can also cause death in people with weak immune systems.
All Victorian cases of rockmelon listeria were identified in "high-risk" patients.
As a result of the outbreak, the NSW Food Authority may apply additional regulatory actions or supervision to the rockmelon industry to ensure compliance and to see improved safety outcomes.
About a third of people who contract listeria in NSW will die from it, but most of the cases are never related to an outbreak, a NSW Health statement said on Friday.
LISTERIA LINKED TO ROCKMELONS
- 19 cases nationwide
- Eight cases in Victoria, three people dead, including a man in his 80s
- Six cases in NSW, a man and woman dead
- Four cases in Queensland, no deaths
- One case in Tasmania, no deaths
- The average age of a listeria patient is 78 years
Australian Associated Press
