The health authorities say there is no link between a patient who was seen at the Singapore General Hospital (SGH) for listeriosis and the consumption of contaminated rock melons from Australia, according to preliminary investigations.

The Ministry of Health (MOH) told The Sunday Times last Friday there is still no report of anyone here having contracted the bacterial disease as a result of eating the rock melons, which have made 17 people ill in Australia and killed four.

All rock melons from Australia are in the process of being recalled by the authorities.

The ministry said it was notified by SGH of a case of listeriosis last Tuesday. Further tests are ongoing to determine the source of infection.

A WhatsApp message circulated last Friday claimed that someone who ate rock melons from Sheng Siong has ended up as the "first case of listeria in SGH".

The outbreak in Australia is linked to contaminated rock melons from a farm in New South Wales. Consignments of melons from the farm were found to have been exported to Singapore.

Consumers should seek medical attention as early as possible if they develop fever and muscle aches that are preceded by diarrhoea or other gastrointestinal symptoms, appearing within 70 days of eating Australian rock melons, the ministry said.

"We will continue to monitor the situation closely," said the MOH spokesman.

Tiffany Fumiko Tay