In the wake of recent cases of listeriosis in the USA linked to ice cream manufactured by Blue Bell Creameries, the Food and Drug Administration (FDA) has published “inspectional observations” from their most recent inspections at three of the company’s production sites.
As of April 20, 2015, a total of ten patients infected with several strains of Listeria monocytogenes were reported from Arizona (1), Kansas (5), Oklahoma (1), and Texas (3). Illness onset dates ranged from January 2010 to January 2015 and three deaths were reported from Kansas.
Epidemiological and microbiological investigation of these cases has established links with ice cream products made by Blue Bell Creameries at a facility in Oklahoma. Listeria monocytogenes has also been isolated from products made at the company’s Texas facility. Blue Bell has recalled all potentially contaminated products and has suspended production at the Oklahoma plant.
The FDA carried out inspections at the Blue Bell production facilities in Brenham, Texas, Broken Arrow, Oklahoma, and Sylacauga, Alabama and has now published the inspectors’ observations. These highlight a number of hygiene and processing problems identified at the three facilities, including inadequate microbiological testing, poor cleaning and sanitising procedures and potential contamination of product by condensate drip from poorly designed equipment.
There have also been some reports that the contamination levels found in ice cream samples implicated in the outbreak were unusually low (1 – 10 CFU/g). Until now, it has been thought that levels of 100 CFU/g or more were necessary to cause infection, even in vulnerable people. This outbreak, along with at least one other unrelated ice cream recall for Listeria contamination, is likely to prompt a review of microbiological safety in the ice cream industry.
The FDA inspection observations from the three Blue Bell Creameries sites and an update on the investigation can be found here.