Salmonella in Rockmelon
In Australia, the New South Wales Food Authority (NSWFA) was recently involved in a national incident involving a Salmonella outbreak in rock melons. During October 2006, 133 patients who had been infected with Salmonella Saintpaul were reported to the National Notifiable Diseases Surveillance System (NNDSS). Of these, 54 were from NSW, representing a significant increase in usual case numbers – approximately 36 annually in NSW). Cases of Salmonella Saintpaul were also reported in Victoria, Australian Capital Territory, Tasmania and South Australia. NSW Health interviewed infected people about all food eaten in the few days before becoming ill. The most common food was rock melon.
As a result of these interviews, a case control study commenced on October 24 to determine if there was a statistical link between Salmonella Saintpaul and any of the commonly mentioned foods. A case-control study is an internationally recognized way of investigating outbreaks and involves interviewing cases (ill people) and controls (people not ill) with a standard questionnaire about food eaten over a set time period. Rock melon was the only food statistically associated with illness and was consumed by over 70% of cases, compared to only 13% of controls.
On the basis of initial interviews from Salmonella Saintpaul cases, the Food Authority commenced an investigation to trace the source from retail stores back to farm. Retail stores provided details of wholesalers who were then contacted. As a result of the Authority investigation, common rock melon processors and growers were identified. Environmental investigations conducted at farms in different states revealed issues requiring further attention. The horticulture industry has been proactive in working to address these issues and is cooperating with various government agencies across Australia to ensure the issue is resolved.
By early November, case numbers declined, signaling the outbreak was over. Consumers can be confident that Australian fresh produce is as
safe as it can be and should be a part of a healthy diet.
