SYDNEY • A fourth person has died after consuming a melon contaminated with listeria, the Australian authorities said yesterday, in an outbreak that has affected 17 people.

Cases first came to the attention of health officials last month, with the source traced back to a farm in New South Wales (NSW) state.

"There have been two deaths in NSW and two in Victoria," NSW Health said in an update, adding that two new cases took the total affected nationally to 17.

Dr Vicky Sheppeard, director of communicable diseases at NSW Health, said all contaminated rock melons, or cantaloupes, were recalled from the market on Feb 28.

"Typically around one-third of people who fall ill with listeriosis die every year. Most of the cases are never related to an outbreak like this one we're seeing with the rock melon contamination," she said.

Listeria is a commonly found bacteria and for many people who consume foods that contain it, it does not cause illness. But it can pose a threat to the elderly, pregnant women or those with conditions like diabetes or cancer.

Listeriosis begins with flu-like symptoms including chills, fever and muscle aches. It has an incubation period of up to 70 days.

Two consignments of rock melons from the affected farm in Australia were imported and available for sale in Singapore from Feb 12 to March 2.

The Agri-Food and Veterinary Authority (AVA) said in a statement on Monday that they were being sold at Sheng Siong supermarket outlets and wet markets. A recall by the Australian health authorities has been completed, after AVA worked with importers to remove the remaining unsold melons.

There has been no further import of rock melons from the affected grower, and import has been suspended, AVA said, adding that no rock melons currently available for sale are involved in the recall.

AVA is following up with the Australian authorities for updates, and has taken samples of locally sold rock melons from other sources for food safety tests, it said.

AGENCE FRANCE-PRESSE