UPDATE
NSW Health is urging high risk groups to be wary of foods that cause listeriosis, confirming there are now 15 cases linked to the national rockmelon outbreak, three of whom have died.
Dr Vicky Sheppeard, Director Communicable Diseases NSW Health, said four of the additional cases are from Victoria and one is from Tasmania. The onset of their illness occurred the week after the initial ten cases, most recently on February 22.
“All 15 cases are elderly people, and most of them have significant underlying health conditions,” Dr Sheppeard said.
“Six of these cases, including two of the people who died, are from NSW.
“We can confirm that 13 of the 15 cases consumed rockmelon before the onset of their illness. People vulnerable to listeriosis should discard any rockmelon purchased before March 1.”
Listeriosis starts with flu-like symptoms such as fever, chills, muscle aches, nausea, and sometimes diarrhoea. The symptoms can take a few days or even up to six weeks to appear after eating contaminated produce.
Listeria is found widely in the environment and rarely causes serious illness in the general population, but for vulnerable people, such as those who are over 70, pregnant, or have diabetes, cancer or suppressed immune systems, it can be extremely serious or even life threatening.
Typically around one third of cases die.
EARLIER
Australians have been urged to throw out rockmelon they have previously purchased after a listeria outbreak that has left two people in NSW dead.
Ten elderly people across Australia, including six from NSW, were diagnosed with the infection after consuming rockmelon and becoming ill between January 17 and February 9, the NSW Food Authority said in a statement on Wednesday.
Two of the six who became ill in NSW subsequently died, a NSW Health spokeswoman confirmed.
The outbreak has been linked to a rockmelon grower in Nericon in the NSW Riverina region with the company voluntarily ceasing production after being notified of the contamination.
The Australian Melon Association has urged people to remove or return any rockmelons purchased before Wednesday.
"Any current rockmelon bought before today, discard or take it back to the shop," Australian Melon Association industry development manager Dianne Fullelove told AAP on Wednesday.
"Fruit on the shelf now is from farms that are not implicated."
There have been 15 cases of listeria infection in Australia this year in total. Ten are being blamed on the contaminated rockmelon.
"Eating foods that contain listeria bacteria does not cause illness in most people, but in higher risk groups it can result in severe illness and even death so it's vitally important these people take extra care at all times," NSW Health's communicable diseases director Dr Vicky Sheppeard said last week.
Listeria starts with flu-like symptoms such as fever, chills, muscle aches, nausea and sometimes diarrhoea but the symptoms can take a few days or weeks to appear after eating contaminated produce.
The infection is particularly dangerous to the elderly, pregnant women and people who have underlying health conditions such as cancer, diabetes, heart and kidney disease.
Vulnerable people should avoid pre-cut melons such as rockmelon or watermelon.
People at risk should consult their doctor as soon as possible if symptoms appear.
LISTERIA: WHAT IT IS, THE RISKS, AND HOW TO AVOID IT
- Listeria is everywhere in the environment
- It's a type of bacterium that infects humans and other warm-blooded animals through contaminated food
- It's found in dirty water, irrigation water, soil and fertiliser.
- Soft cheeses such as Camembert; cold chicken and deli meats; raw seafood and cold seafood such as smoked salmon; ice cream, fresh fruit and bagged vegetables can also carry Listeria
- Infection can also occur through contact with animals and pests and insufficient cleaning of contaminated fruit and unclean hands
WHO IS SUSCEPTIBLE ... AND THE SYMPTOMS
- Pregnant women, infants, the elderly and those with compromised immune systems are most at risk
- Listeria starts with flu-like symptoms such as fever, chills, muscle aches, nausea and sometimes diarrhoea
- The time from consuming the bacterium to showing the signs of illness can often be between 8 to 90 days.
- Some people end up in hospital with dehydration
HOW TO AVOID IT
- Don't buy bruised or damaged fruit, wash it before eating and refrigerate within two hours of slicing
- Avoid foods past their 'best before' or 'use by' date
- Cook foods thoroughly
- Reheat food until it is steaming hot
- Refrigerate leftovers promptly and use within 24 hours, or freeze
- Ready to eat food should never be stored in the fridge for too long as Listeria is one of the few pathogens that can grow in the refrigerator
Source: Food Authority NSW, Food Safety Information Council
Australian Associated Press