02 March 2018

​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 22 February.

“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 1 March.”

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.

NSW Health is continuing to work with the NSW Food Authority and other state and territory departments on the investigation into the outbreak. The NSW Food Authority has advised the outbreak has been linked to one grower in Nericon NSW and is continuing its investigation to determine the cause.

People at risk should consult their local doctor as early as possible should symptoms appear. There are no useful tests for the infection prior to the onset of symptoms.

NSW Health reminds all people at risk of listeriosis to avoid the following foods:

  • pre-cut melons such as rockmelon or watermelon
  • pre-packed cold salads including coleslaw and fresh fruit salad
  • pre-cooked cold chicken, cold delicatessen meats, pâté
  • raw seafood, uncooked smoked seafood (e.g. smoked salmon)
  • unpasteurised milk or milk products, soft cheeses (e.g. brie, camembert, ricotta or blue-vein)
  • sprouted seeds or raw mushrooms.

For further information see the Listeriosis fact sheet and the NSW Food Authority Food safety during pregnancy brochure.