The US Centers for Disease Control and Prevention (CDC) said five rare DNA fingerprints of Listeria were included in the investigation from 10 states with the first case in June 2010.
Twenty-eight people were hospitalized. Six illnesses were pregnancy-related; one resulted in a fetal loss and three deaths were reported from California (2) and Ohio (1).
Traceback to Karoun Dairies Inc
Soft cheeses distributed by Karoun Dairies Inc were the likely source of the Listeria monocytogenes outbreak.
Twenty-one of the 28 ill people with available information reported eating soft cheeses in the month before becoming ill.
Three of seven specified a brand of soft cheese reported brands distributed by Karoun Dairies of San Fernando, California.
An additional ill person likely ate cheese from Karoun Dairies Inc based on a description of the cheese packaging and label. No other brand of soft cheese was reported more than once.
Whole genome sequencing (WGS) analysis of two environmental samples collected by the FDA in September from the Central Valley Cheese manufacturing facility in Turlock, California, showed L. monocytogenes that was highly related to the outbreak strains in ill people.
Central Valley Cheese manufactures cheese for Karoun Dairies Inc. WGS analysis determined five environmental samples from the same facility in 2010 were also highly related to the outbreak strains.
The number of ill people from each state was California (18), Colorado (1), Illinois (2), Massachusetts (2), Michigan (1), New York (2), Ohio (1), Tennessee (1), Virginia (1), and Washington (1).
Ill people ranged in age from less than 1 year to 92, and the median age was 73 and 70% were female.
Karoun Dairies Inc recalled and topped distributing certain cheeses last month.
The products were distributed to retail outlets, including food service outlets and supermarkets throughout the US.
They are vacuum packed, in jars or in pails, and have weights varying from 5 ounces to 30 pounds.
FSANZ annual review
Meanwhile, 56 food recalls, mainly due to undeclared allergens and microbial contamination (predominantly L. monocytogenes) have been reported in the Food Standards Australia New Zealand (FSANZ) 2014-15 annual report.
A total of 20 were due to undeclared allergens – ranging from multiple allergens (6), peanut, wheat and eggs (all 3), dairy (2) and sesame, tree nuts and soy (all 1).
Microbial contamination prompted 19 recalls such as L. monocytogenes (8), “other” microbial contaminant and Salmonella (3 each), viral contaminant (2) and E.coli, staphylococcus and “other” bacterial contaminant (all 1).
The Australia New Zealand Food Standards Code was also revised and will take effect in March 2016.
Steve McCutcheon, CEO of FSANZ, also described the response to a foodborne illness outbreak associated with imported ready-to-eat berries in early 2015.
“FSANZ worked closely with the Department of Agriculture in providing risk assessment advice on hepatitis A virus in ready-to-eat berries to help the department implement appropriate interventions under the Imported Food Control Act 1992,” he said.
“While we were assessing the potential risk, we also successfully activated our food incident response role, working with importers, food retailers and national, state and territory government agencies to implement a coordinated food recall and communication strategy.
“The net result saw potentially contaminated product removed quickly from the market and significant media coverage to alert consumers to check their freezers and dispose of any implicated products.”