There have been 86 reported cases of Salmonella Hvittingfoss (S. Hvittingfoss) nationally with 43 in New South Wales (NSW) between June 14 and August 1. The majority are from the greater Sydney metropolitan area.
Nine cases are in Western Australia, eight from Queensland, six in Victoria and two in the Australian Capital Territory. No deaths have been reported.
Affected people are of varied ages, but 49% in NSW were in children under five years old.
Product recall and consumer advice
The Northern Territory based company “Red Dirt” has recalled product after detection of Salmonella bacteria by South Australian authorities on August 2. The strain in the samples has not yet been determined.
Dr Jeremy McAnulty, director of health protection NSW, said it was working with the NSW Food Authority and other jurisdictions on an investigation into possible sources.
“Although the source of the outbreak at this stage is still unclear, consumption of rockmelon is common to many of the patients in NSW,” he said.
“As a precaution, anyone who may have rockmelon in their home and is unsure of its origin should not eat the product.
“Like many other fresh foods, sliced melons can be easily contaminated with Salmonella bacteria and should be kept refrigerated.”
Overseas evidence suggests contaminated water, fertiliser, contact with pests/animals or insufficient cleaning of rockmelons prior to sale could contribute to them becoming contaminated with Salmonella, said the NSW Food Authority.
FSANZ said until further information is available the best advice is that consumers, especially infants, the elderly, pregnant women or people with compromised immune systems, should not consume rockmelon.
The Australian Melon Association said other types of melons are not implicated.
“The industry is genuinely concerned for the health of consumers involved in this outbreak,” it said in a statement.
“The Australian melon industry is a well-organised body of growers who understand food safety risks well. All growers are currently being contacted and appropriate support and advice is being provided.
“The industry is working closely with government food safety investigators to respond to this incident and will redouble its efforts to eliminate foodborne illness.”
Professor Paddy Phillips, South Australia Health chief medical officer, said all contaminated rock melon will be removed from the supply chain but until further notice, people should avoid eating it.
A total of 20 cases have been reported in the state since late June 2016. South Australians affected are aged from eight months through to 81, with 65% under five years.
Between 2011 and 2016, NSW received an average of fewer than two notifications of S. Hvittingfoss per month.
On average South Australia sees about two cases of Salmonella Hvittingfoss per year.
Rockmelons have been linked to Salmonella poisonings in the past, including in the US during the 1950s, 1960s and in 2002.
An outbreak in October 2006 in Australia resulted in more than 120 salmonellosis cases associated with having rockmelon.
People can start experiencing symptoms of Salmonella infection between 12 and 72 hours after exposure and symptoms can last for three to seven days.
E. coli O157 update
Meanwhile, Health Protection Scotland said the number of confirmed cases of E. coli O157 associated with eating Dunsyre Blue cheese made from unpasteurised milk has risen to 18.
The agency said Dunsyre Blue remains the most likely cause of the cases. Errington Cheese has recalled suspected batches.
Two additional cases developed symptoms between 2 and 15 July.
There are 14 cases in Scotland across seven NHS Boards and four in England with one patient being treated in hospital.