April 6, 2018
Listeria outbreaks have been making headlines in Australia and South Africa.
The source of the outbreak in South Africa, where a large number of cases and deaths have been reported, has been identified as a ready to eat processed meat. While the implicated food recall was implemented on the 4 March 2018, it is expected new cases will continue to be reported for some time, as the incubation period for Listeriosis can be up to 70 days.
The National Institute for Communicable Diseases (NICD) has undertaken whole genome sequencing on 439 case isolates of Listeria monocytogenes to date with 92% belonging to sequence type 6 (ST6). The high frequency of this particular strain confirms a single isolate as the source of infection in almost all reported cases.
The same strain was also found at the production facilities identified as the source, in both the post-cooking environment and on product.
In Australia, the outbreak has been attributed to Rock Melon, from the NSW Riverina region. The NSW Food Authority reports 4 deaths and 17 cases nationally as of 13 March 2018. The Food Authority is working with the supplier, and the industry to ensure safe supply now and in the future.
The melon industry is currently undertaking research with the ARC Training Centre for Food Safety in the Fresh Produce Industry into the best practice in food safety on rockmelon farms.
To see our range of products for Listeria testing go to Listeria Landing Page
National Institute for Communicable Diseases. Situation Update on Listeriosis Outbreak, South Africa 29 March 2018
National Institute for Communicable Diseases. Statement Regarding the source of the Listeriosis Outbreak 2 April 2018
New South Wales Food Authority supports rock melon industry 13 March 2018